#Postgresql

Last updated    - V6 (03-Oct-2025)

Key Concepts

Level	Topic	Subtopics
Basic	Installation & Setup	Download, initdb, configuration, pg_ctl, pgAdmin
	Architecture Overview	Processes (postmaster, bgwriter, wal writer), memory, WAL, storage engine
	Data Types	Numeric, Text, Boolean, Date/Time, UUID, Arrays
	Schema & Tables	CREATE, ALTER, DROP, constraints, tablespaces
	Basic Queries	SELECT, INSERT, UPDATE, DELETE
	Constraints	PRIMARY KEY, FOREIGN KEY, UNIQUE, CHECK
	psql Client	Meta commands (\d, \i, \dt), scripting
	Import/Export	COPY, pg_dump, pg_restore, \copy
	Basic Functions	String, Math, Aggregate, Conversion
	Transactions	BEGIN, COMMIT, ROLLBACK, savepoints
Intermediate	Joins & Subqueries	INNER, LEFT, RIGHT, FULL, Nested queries, CTEs
	Indexing	B-Tree, Hash, GIN, GiST, covering indexes
	Views	Simple Views, Materialized Views, refresh strategies
	Triggers & Rules	BEFORE/AFTER triggers, INSTEAD OF triggers, Rules
	Functions & PL/pgSQL	SQL functions, PL/pgSQL basics, error handling
	Window Functions	RANK, ROW_NUMBER, PARTITION BY, LEAD, LAG
	Sequences & Identity	SERIAL, BIGSERIAL, GENERATED ALWAYS, currval(), nextval()
	JSON & JSONB	Storage, operators, indexing (GIN), functions
	Error Handling	EXCEPTION blocks, raise notice/error/warning
	Data Modeling	Normalization, relationships, schema design
Advanced	Query Optimization	EXPLAIN, ANALYZE, query planner
	Partitioning	Range, List, Hash, default partitions
	Table Inheritance	Parent-child tables, constraints, performance
	Locks & Concurrency	Row locks, Deadlocks, MVCC
	Vacuum & Analyze	Autovacuum, statistics, bloat removal
	Extensions	PostGIS, pg_stat_statements, hstore, uuid-ossp
	Full Text Search	tsvector, tsquery, dictionaries, ranking
	Parallel Query	Parallel scan, joins, aggregate
	Advanced Security	Row-Level Security (RLS), Policies, GRANT/REVOKE
	Large Objects	BYTEA, TOAST, pg_largeobject API
Expert	High Availability	Streaming replication, Logical replication, failover
	Backup & Recovery	pg_dump, PITR, WAL archiving, pgBackRest, Barman
	Sharding & Scaling	Citus, FDWs, partitioned scaling
	Advanced Indexing	BRIN, Bloom, Expression indexes, Partial indexes
	Monitoring & Tuning	pg_stat_statements, logs, auto_explain, tuning params
	System Catalogs	pg_class, pg_attribute, pg_index, pg_roles
	Advanced PL/pgSQL	Packages, dynamic SQL, performance best practices
	Cross-DB Integration	dblink, postgres_fdw, foreign data wrappers
	Migration Tools	pg_upgrade, logical replication for migration, data migration strategies
	Enterprise Deployment	Kubernetes, cloud deployment, scaling strategies

Interview question

Basic Level

1. What is PostgreSQL and how is it different from other RDBMS like MySQL or Oracle?
2. What are the main features of PostgreSQL?
3. Explain the architecture of PostgreSQL.
4. How do you install PostgreSQL on Linux and Windows?
5. What is psql in PostgreSQL?
6. How do you create a new database in PostgreSQL?
7. How do you list all databases in PostgreSQL?
8. What are schemas in PostgreSQL?
9. How do you connect to a PostgreSQL database using psql?
10. Explain the difference between CHAR, VARCHAR, and TEXT in PostgreSQL.
11. How do you create a table in PostgreSQL?
12. What are the different data types available in PostgreSQL?
13. How do you insert data into a PostgreSQL table?
14. How do you update and delete data in PostgreSQL?
15. What are sequences in PostgreSQL?
16. How do you create a sequence in PostgreSQL?
17. What is a primary key in PostgreSQL?
18. How do you define a foreign key in PostgreSQL?
19. What are indexes in PostgreSQL?
20. How do you create an index in PostgreSQL?
21. What is the difference between DELETE and TRUNCATE?
22. What is the purpose of the RETURNING clause in PostgreSQL?
23. How do you enable case-insensitive search in PostgreSQL?
24. Explain the difference between NULL and an empty string.
25. How do you backup and restore a PostgreSQL database?

---

Intermediate Level

1. What are PostgreSQL system catalogs?
2. How does PostgreSQL handle transactions?
3. Explain the concept of MVCC (Multi-Version Concurrency Control).
4. What is the difference between COMMIT and ROLLBACK?
5. How do you implement foreign key constraints with cascading actions?
6. What is a materialized view in PostgreSQL?
7. How do you refresh a materialized view?
8. Explain the difference between VIEW and MATERIALIZED VIEW.
9. What are window functions in PostgreSQL?
10. How do you use ROW_NUMBER(), RANK(), and DENSE_RANK()?
11. What are PostgreSQL extensions? Give examples.
12. What is the pgAdmin tool used for?
13. How do you monitor queries in PostgreSQL?
14. What is the EXPLAIN command used for?
15. How do you optimize queries in PostgreSQL?
16. Explain the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
17. How do you implement recursive queries in PostgreSQL?
18. What is the difference between NOW() and CURRENT_DATE?
19. Explain COALESCE() function in PostgreSQL.
20. How do you use JSON and JSONB data types in PostgreSQL?
21. How do you create and query an array column in PostgreSQL?
22. What are PostgreSQL operators for pattern matching?
23. Explain IS DISTINCT FROM operator in PostgreSQL.
24. How do you grant and revoke privileges in PostgreSQL?
25. What is the role of pg_hba.conf?

---

Advanced Level

1. Explain Write-Ahead Logging (WAL) in PostgreSQL.
2. How does PostgreSQL ensure data consistency?
3. What are the different types of indexes in PostgreSQL?
4. When should you use GIN vs BTREE indexes?
5. Explain Partial Indexes in PostgreSQL.
6. What is a covering index in PostgreSQL?
7. How do you implement full-text search in PostgreSQL?
8. Explain the difference between TO_CHAR() and TO_DATE().
9. How does PostgreSQL handle concurrency and locking?
10. What are advisory locks in PostgreSQL?
11. How does VACUUM work in PostgreSQL?
12. What is the difference between VACUUM and VACUUM FULL?
13. What is ANALYZE used for?
14. How does PostgreSQL query planner work?
15. What are parallel queries in PostgreSQL?
16. Explain logical vs physical replication.
17. How do you configure replication in PostgreSQL?
18. What are hot standby servers in PostgreSQL?
19. Explain Point-In-Time Recovery (PITR) in PostgreSQL.
20. How do you implement partitioning in PostgreSQL?
21. Explain the difference between range and list partitioning.
22. What is a foreign data wrapper (FDW)?
23. How do you connect PostgreSQL with other databases using FDW?
24. What are stored procedures in PostgreSQL?
25. How do you write PL/pgSQL functions?

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Expert Level

1. Explain PostgreSQL?s process architecture (postmaster, background workers, autovacuum).
2. How do you handle deadlocks in PostgreSQL?
3. What strategies can be used for PostgreSQL performance tuning?
4. How do you tune work_mem, shared_buffers, and effective_cache_size?
5. What are PostgreSQL tablespaces?
6. How do you create and use a tablespace?
7. What is sharding in PostgreSQL? How can it be implemented?
8. How does PostgreSQL differ from distributed databases like CockroachDB or Citus?
9. What is the difference between synchronous and asynchronous replication?
10. How do you set up synchronous replication?
11. How do you monitor replication lag in PostgreSQL?
12. How do you implement high availability (HA) in PostgreSQL?
13. Explain connection pooling in PostgreSQL.
14. What is PgBouncer and how is it used?
15. How do you implement partition pruning in PostgreSQL?
16. Explain JIT (Just-In-Time) compilation in PostgreSQL.
17. How do you debug performance issues in PostgreSQL queries?
18. What are generated columns in PostgreSQL?
19. How do you implement Row-Level Security (RLS)?
20. How do you use event triggers in PostgreSQL?
21. Explain logical decoding in PostgreSQL.
22. What is WAL archiving and how is it configured?
23. How does PostgreSQL handle large objects (LOBs)?
24. What are common PostgreSQL anti-patterns to avoid?
25. Compare PostgreSQL with NoSQL databases in terms of scalability and flexibility.

Related Topics

#CoreJava_08

Last updated    - V4 (16-Sep-2025)

Key Concepts

Topic	Sub-Topics	Basic	Intermediate	Advanced	Expert
Lambda Expressions	Syntax, Scope, Variable capture, Method references, Constructor references	✔️	✔️	✔️	✔️
Functional Interfaces	Predicate, Consumer, Supplier, Function, BiFunction, UnaryOperator, BinaryOperator, Custom FI	✔️	✔️	✔️	✔️
Stream API - Basics	Creating streams, map(), filter(), forEach(), count(), collect()	✔️	✔️
Stream API - Intermediate	distinct(), sorted(), limit(), skip(), peek(), Optional + Streams		✔️	✔️
Stream API - Advanced	reduce(), flatMap(), groupingBy(), partitioningBy(), joining(), summarizing, parallelStream()		✔️	✔️	✔️
Stream API - Expert	Custom collectors, Stream performance tuning, Spliterator, Lazy evaluation, Infinite streams			✔️	✔️
Optional Class	of(), ofNullable(), empty(), isPresent(), ifPresent(), orElse(), orElseGet(), orElseThrow()	✔️	✔️
Date and Time API (java.time)	LocalDate, LocalTime, LocalDateTime, Instant, ZoneId, OffsetDateTime, Period, Duration	✔️	✔️	✔️
Date and Time Formatting	DateTimeFormatter, Custom patterns, Parsing, Timezone conversions		✔️	✔️
Default & Static Methods in Interfaces	Default methods, Static methods, Diamond problem, Multiple inheritance resolution	✔️	✔️	✔️	✔️
CompletableFuture & Concurrency	supplyAsync(), runAsync(), thenApply(), thenAccept(), thenCombine(), allOf(), anyOf()		✔️	✔️	✔️
Asynchronous Programming	Exception handling in CompletableFuture, Non-blocking computations, Chaining futures			✔️	✔️
Nashorn JavaScript Engine	Script execution, Bind Java Objects, Invoke Java methods, External JS files, Performance		✔️	✔️
Collections Enhancements	forEach(), removeIf(), replaceAll(), computeIfAbsent(), computeIfPresent(), merge()	✔️	✔️	✔️
Map API Improvements	getOrDefault(), putIfAbsent(), replaceAll(), compute(), replace(), new traversal APIs	✔️	✔️	✔️
StringJoiner & Collectors	joining(), delimiters, prefix & suffix, Collectors.toList(), toSet(), toMap()	✔️	✔️	✔️
Base64 Encoding/Decoding	Basic, URL, MIME encoding & decoding	✔️	✔️
Arrays Enhancements	parallelSort(), setAll(), parallelPrefix(), Arrays.stream()	✔️	✔️	✔️
Annotations (Java 8)	@FunctionalInterface, @Repeatable, Type Annotations, @Target, @Retention	✔️	✔️	✔️
Method References	Reference to static methods, instance methods, constructors	✔️	✔️	✔️
Parallel Programming	Parallel streams, ForkJoinPool, Performance considerations		✔️	✔️	✔️
Spliterator API	tryAdvance(), forEachRemaining(), characteristics(), estimateSize(), parallel iteration			✔️	✔️
Security & Java 8	SecureRandom with streams, Optional null-safety, Immutable Date-Time API	✔️	✔️	✔️	✔️
Miscellaneous Utilities	Objects.requireNonNullElse(), Files.lines(), Instant.now(), Comparator.comparing()	✔️	✔️	✔️	✔️
Performance Tuning	Streams vs loops, Parallel stream overhead, Memory considerations			✔️	✔️
Testing with Java 8	Testing Lambdas, Streams, and CompletableFuture, Mocking functional interfaces		✔️	✔️	✔️

Interview question

1. Lambda Expressions (25 Questions)

1. What is a lambda expression in Java 8?
2. Why were lambda expressions introduced in Java?
3. Explain the syntax of a lambda expression with an example.
4. How does a lambda expression differ from an anonymous class?
5. Can lambda expressions access local variables from the enclosing scope?
6. What is variable capture in lambdas?
7. What are the restrictions on accessing variables inside lambdas?
8. How does this behave inside a lambda expression?
9. Can lambdas be recursive? How?
10. How do you use lambdas with functional interfaces?
11. What is the target type of a lambda expression?
12. Can you overload methods with lambda parameters?
13. How does type inference work in lambda expressions?
14. Can lambdas throw checked exceptions?
15. Can lambdas have multiple return statements?
16. Difference between -> and :: operators in Java 8.
17. What are the advantages of using lambdas?
18. How are lambdas internally implemented in Java?
19. Can lambdas be serialized?
20. How do you debug lambda expressions?
21. Can you assign a lambda to a variable?
22. How do lambdas improve iteration over collections?
23. Give an example of using a lambda with Runnable.
24. How does the compiler determine the type of a lambda?
25. What are some real-world use cases of lambdas?

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2. Functional Interfaces (25 Questions)

1. What is a functional interface in Java 8?
2. Explain the @FunctionalInterface annotation.
3. Give 5 examples of built-in functional interfaces.
4. Difference between Predicate and Function.
5. Difference between Consumer and Supplier.
6. What is a UnaryOperator? Example?
7. What is a BinaryOperator? Example?
8. How do you chain functional interfaces like Predicate and Function?
9. Can functional interfaces have default methods?
10. Can functional interfaces have static methods?
11. Can a functional interface extend another interface?
12. What happens if you declare two abstract methods in a functional interface?
13. How does type inference work with functional interfaces?
14. Can a functional interface be generic?
15. What are primitive specializations of functional interfaces?
16. Can functional interfaces throw exceptions?
17. How do you implement a custom functional interface?
18. How do you use method references with functional interfaces?
19. What is the difference between apply() in Function and test() in Predicate?
20. Can functional interfaces be Serializable?
21. What is the role of java.util.function package?
22. When should you explicitly use @FunctionalInterface?
23. Can functional interfaces override equals() and hashCode()?
24. How do functional interfaces enable functional programming in Java?
25. Real-world use case of functional interfaces?

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3. Stream API Basics (25 Questions)

1. What is the Stream API in Java 8?
2. Difference between a Collection and a Stream?
3. How do you create a stream from a list?
4. What are intermediate operations in streams?
5. What are terminal operations in streams?
6. Explain lazy evaluation in streams.
7. Difference between map() and flatMap().
8. What does the filter() operation do?
9. How do you sort a stream?
10. What is the use of forEach() in streams?
11. Difference between sequential and parallel streams.
12. How do you collect stream results into a list?
13. How do you collect stream results into a set?
14. What is the reduce() operation in streams?
15. Difference between findFirst() and findAny().
16. How do you use limit() and skip() in streams?
17. How does distinct() work in streams?
18. Explain peek() and its use case.
19. Can you reuse a stream after a terminal operation?
20. How do you create an infinite stream?
21. How does performance differ between loops and streams?
22. Can streams work on primitive types?
23. How do you debug a stream pipeline?
24. How does short-circuiting work in streams?
25. Real-world use case of streams?

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4. Optional Class (25 Questions)

1. What is Optional in Java 8?
2. Why was Optional introduced?
3. How do you create an Optional object?
4. Difference between Optional.of() and Optional.ofNullable().
5. What does Optional.empty() return?
6. How do you check if a value is present in Optional?
7. Difference between isPresent() and ifPresent().
8. How do you provide a default value with Optional?
9. Difference between orElse() and orElseGet().
10. Difference between orElse() and orElseThrow().
11. How do you transform values inside Optional using map()?
12. Difference between map() and flatMap() in Optional.
13. How do you filter values in Optional?
14. Can Optional itself be null?
15. Can Optional be used for method parameters?
16. What are drawbacks of using Optional excessively?
17. Can Optional be serialized?
18. How do you return Optional from repository methods?
19. Can you use Optional with Streams?
20. How do you combine multiple Optionals?
21. Is Optional thread-safe?
22. Can Optional hold collections?
23. What is the difference between Optional in Java and Maybe in other FP languages?
24. Should Optional be used in DTOs?
25. Real-world use cases of Optional?

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5. Date and Time API (25 Questions)

1. What is the new Date/Time API in Java 8?
2. Why was it introduced when we already had Date and Calendar?
3. What is LocalDate?
4. What is LocalTime?
5. What is LocalDateTime?
6. What is ZonedDateTime?
7. How do you parse and format dates in Java 8?
8. Difference between DateTimeFormatter and SimpleDateFormat?
9. What is Period in Java 8?
10. What is Duration in Java 8?
11. How do you calculate the difference between two dates?
12. How do you add or subtract days from a date?
13. How do you check if a year is a leap year?
14. How do you handle time zones in Java 8?
15. Difference between Instant and LocalDateTime.
16. How do you convert between old Date and new DateTime API?
17. What is Clock in Date/Time API?
18. What is TemporalAdjuster?
19. What is TemporalUnit?
20. How do you get the start and end of a day?
21. What is the difference between OffsetDateTime and ZonedDateTime?
22. How do you compare two dates in Java 8?
23. Can LocalDate represent time?
24. Can LocalTime represent date?
25. Real-world use cases of Date/Time API?

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6. Default & Static Methods in Interfaces (25 Questions)

1. What are default methods in Java 8?
2. Why were default methods introduced?
3. Can interfaces have method implementations in Java 8?
4. How do you define a default method?
5. Can a class override a default method?
6. What happens if two interfaces have the same default method?
7. How do you resolve conflicts in multiple inheritance with default methods?
8. Can interfaces have static methods?
9. How do you call a static method in an interface?
10. Can default methods be abstract?
11. Can interfaces have private methods in Java 8?
12. How do default methods impact backward compatibility?
13. Can constructors be default methods?
14. How do you use default methods with collections?
15. Can default methods call abstract methods?
16. Can default methods be overridden by subclasses?
17. What is the difference between default methods and abstract classes?
18. Can default methods be synchronized?
19. Can default methods throw exceptions?
20. Can default methods call other default methods?
21. Are static methods inherited in interfaces?
22. Can you override static methods from interfaces?
23. Can static methods in interfaces be private?
24. Real-world use case of default methods?
25. Real-world use case of static methods in interfaces?

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7. CompletableFuture & Concurrency (25 Questions)

1. What is CompletableFuture in Java 8?
2. How is CompletableFuture different from Future?
3. How do you create a CompletableFuture?
4. How do you run asynchronous tasks with CompletableFuture?
5. Difference between runAsync() and supplyAsync().
6. What is thenApply() in CompletableFuture?
7. What is thenAccept()?
8. What is thenRun()?
9. Difference between thenCompose() and thenCombine().
10. How do you handle exceptions in CompletableFuture?
11. What is exceptionally() method?
12. What is handle() method?
13. How do you combine multiple CompletableFutures?
14. Difference between allOf() and anyOf().
15. How do you cancel a CompletableFuture?
16. How do you block and get the result?
17. What is join() in CompletableFuture?
18. Difference between join() and get().
19. How do you implement timeouts in CompletableFuture?
20. Is CompletableFuture thread-safe?
21. How do you use custom thread pools with CompletableFuture?
22. Difference between synchronous and asynchronous callbacks?
23. How does CompletableFuture improve parallelism?
24. How do you test CompletableFutures?
25. Real-world use cases of CompletableFuture?

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8. Collections & Map Enhancements (25 Questions)

1. What enhancements were made to collections in Java 8?
2. What is the forEach() method in collections?
3. How do you use removeIf()?
4. What is the replaceAll() method?
5. What is the sort() method in List?
6. How do you use computeIfAbsent() in Map?
7. How do you use computeIfPresent()?
8. How do you use compute()?
9. What is merge() in Map?
10. How do you use getOrDefault() in Map?
11. What is putIfAbsent()?
12. What is replace() in Map?
13. How do you use forEach() in Map?
14. Difference between entrySet() iteration and forEach().
15. How do you sort a Map by values?
16. Can you use streams with collections directly?
17. What is Spliterator?
18. How is Spliterator different from Iterator?
19. What is trySplit() in Spliterator?
20. How do you estimate size in Spliterator?
21. What is the ORDERED characteristic in Spliterator?
22. What is the CONCURRENT characteristic?
23. What is the DISTINCT characteristic?
24. What is the IMMUTABLE characteristic?
25. Real-world use case of collection enhancements?

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9. Streams Advanced (25 Questions)

1. What are parallel streams?
2. How do you create a parallel stream?
3. Difference between sequential and parallel stream performance?
4. What are the pitfalls of parallel streams?
5. How does fork-join framework work with parallel streams?
6. What is Collectors.groupingBy()?
7. What is Collectors.partitioningBy()?
8. Difference between groupingBy() and partitioningBy().
9. What is Collectors.mapping()?
10. How do you join strings using Collectors.joining()?
11. How do you count elements using Collectors.counting()?
12. What is Collectors.summarizingInt()?
13. What is Collectors.averagingDouble()?
14. What is Collectors.reducing()?
15. What is a custom collector?
16. How do you implement your own collector?
17. What is a downstream collector?
18. Difference between reduce() and collect().
19. Can streams be infinite?
20. How do you use Stream.iterate()?
21. How do you use Stream.generate()?
22. What is flatMapToInt()?
23. What is boxed() in streams?
24. What is parallelism level in parallel streams?
25. Best practices for using advanced streams?

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10. Miscellaneous Java 8 Features (25 Questions)

1. What is Nashorn in Java 8?
2. How do you execute JavaScript with Nashorn?
3. What is StringJoiner in Java 8?
4. How do you join strings with a delimiter using StringJoiner?
5. What enhancements were made to String in Java 8?
6. What is the new Base64 API in Java 8?
7. Difference between Encoder and Decoder in Base64.
8. How do you encode and decode a string with Base64?
9. What enhancements were made to Arrays in Java 8?
10. How do you sort an array with a custom comparator in Java 8?
11. What is Arrays.parallelSort()?
12. What is SplittableRandom?
13. How is SplittableRandom different from Random?
14. What enhancements were made to Comparator in Java 8?
15. How do you use comparing() method in Comparator?
16. How do you use thenComparing()?
17. What are annotation enhancements in Java 8?
18. What is repeating annotations?
19. What is type annotation in Java 8?
20. How do you declare type-use annotations?
21. Can annotations be applied to generics in Java 8?
22. Can annotations be inherited in Java 8?
23. What is method parameter reflection in Java 8?
24. What are compact profiles?
25. Summary of miscellaneous features introduced in Java 8?

Related Topics

Lambda Expressions

Functional Interfaces

Stream API

#Azure

Last updated    - V6 (18-Sep-2025)

Key Concepts

Topic	Sub-Topics	Basic	Intermediate	Advanced	Expert
Compute	Virtual Machines, VM Scale Sets, App Services, Azure Functions, Logic Apps	✅	✅	✅	✅
Storage	Blob Storage, Table Storage, Queue Storage, File Storage, Data Lake Gen2	✅	✅	✅	✅
Networking	VNet, Subnets, NSG, Load Balancer, Application Gateway, Front Door, ExpressRoute, VPN Gateway, Traffic Manager	✅	✅	✅	✅
Databases	Azure SQL, Cosmos DB, Synapse, PostgreSQL/MySQL, Managed Instance	✅	✅	✅	✅
Identity & Security	Azure AD, RBAC, MFA, Conditional Access, PIM, Key Vault, Azure Policy	✅	✅	✅	✅
Monitoring & Management	Azure Monitor, Log Analytics, Application Insights, Azure Advisor, Cost Management, Blueprints	✅	✅	✅	✅
Containers & Kubernetes	AKS, ACR, Container Instances, Helm, Service Mesh	✅	✅	✅	✅
Integration Services	Event Grid, Event Hub, Service Bus, API Management	✅	✅	✅	✅
DevOps & Automation	Azure DevOps, Pipelines, Repos, Artifacts, Boards, ARM Templates, Bicep, Automation	✅	✅	✅	✅
AI & ML	Cognitive Services, Azure ML, Databricks, Cognitive Search	✅	✅	✅	✅
Data & Analytics	Data Factory, Synapse, Databricks, HDInsight, Power BI Integration	✅	✅	✅	✅
Hybrid & Multi-Cloud	Azure Arc, Azure Stack, Lighthouse	✅	✅	✅	✅
Migration & DR	Azure Migrate, Site Recovery, Database Migration Service	✅	✅	✅	✅
IoT & Edge	IoT Hub, IoT Edge, Digital Twins, Stream Analytics, Private MEC	✅	✅	✅	✅
Security & Compliance	Security Center, Defender for Cloud, Sentinel, Confidential Computing	✅	✅	✅	✅
Enterprise Governance	Blueprints, Policy, Cost Management, FinOps	✅	✅	✅	✅
Big Data & HPC	HDInsight, Databricks, HPC Clusters	✅	✅	✅	✅
Media & Content Delivery	Media Services, CDN	✅	✅	✅	✅
Blockchain	Azure Blockchain Service, Confidential Ledger	✅	✅	✅	✅
Specialized Workloads	SAP on Azure, HPC, AI Supercomputing	✅	✅	✅	✅

Interview question

Basic Level

1. What is Microsoft Azure?
2. What are the main advantages of using Azure?
3. Explain the difference between IaaS, PaaS, and SaaS.
4. What are Azure Regions and Availability Zones?
5. What is Azure Resource Manager (ARM)?
6. What is an Azure Subscription?
7. What is the difference between Azure Tenant and Subscription?
8. What is Azure Virtual Machine (VM)?
9. What is the difference between VM Scale Sets and Availability Sets?
10. What are Azure App Services?
11. What is Azure Functions?
12. What is Azure Logic Apps?
13. What is Azure Blob Storage?
14. What are the storage tiers in Azure?
15. Difference between Blob, File, Queue, and Table storage.
16. What is an Azure Virtual Network (VNet)?
17. What are Network Security Groups (NSGs)?
18. What is Azure Load Balancer?
19. What is Application Gateway?
20. What is ExpressRoute?
21. What is Azure SQL Database?
22. What is the difference between SQL Database and Managed Instance?
23. What is Cosmos DB?
24. What is Azure Synapse Analytics?
25. What is Azure Active Directory (AAD)?
26. What is the difference between Azure AD and AD DS?
27. What is Role-Based Access Control (RBAC)?
28. What is Multi-Factor Authentication (MFA) in Azure?
29. What is Azure Key Vault?
30. What is Azure Monitor?
31. What is Log Analytics in Azure?
32. What is Application Insights?
33. What is Azure Advisor?
34. What is Azure Kubernetes Service (AKS)?
35. What is Azure Container Registry (ACR)?
36. What are Azure Container Instances?
37. What is Azure Event Grid?
38. What is Azure Service Bus?
39. What is Azure DevOps?
40. What are Pipelines in Azure DevOps?
41. What are Repos and Artifacts in Azure DevOps?
42. What are Boards in Azure DevOps?
43. What is Cognitive Services in Azure?
44. What is Azure Machine Learning?
45. What is Azure Databricks?
46. What is Azure Data Factory?
47. What is Azure Arc?
48. What is Azure Stack HCI?
49. What is Azure Site Recovery?
50. What is Azure Migrate?

---

Intermediate Level

1. How does Azure VM Scale Sets provide scalability?
2. What are Availability Zones vs Availability Sets?
3. How do you secure Azure Virtual Machines?
4. How do you configure Azure Bastion?
5. What is Azure Application Gateway with WAF?
6. How does Azure Front Door work?
7. What is the difference between Azure Load Balancer and Front Door?
8. What is a VNet Peering?
9. Difference between VPN Gateway and ExpressRoute.
10. What is Private Link in Azure?
11. What is a Service Endpoint in Azure Networking?
12. How does Cosmos DB handle partitioning?
13. What are consistency levels in Cosmos DB?
14. How does Cosmos DB provide multi-region replication?
15. What is Synapse Analytics used for?
16. What is PolyBase in Synapse?
17. What is Azure Data Lake Storage Gen2?
18. What are Managed Identities in Azure?
19. What is Conditional Access in Azure AD?
20. What is Privileged Identity Management (PIM)?
21. How does Azure Key Vault integrate with applications?
22. What are Diagnostic Settings in Azure Monitor?
23. How does Log Analytics query language (KQL) work?
24. How does Application Insights help in distributed tracing?
25. What is Azure Policy?
26. What is the difference between Azure Monitor and Azure Security Center?
27. What is Azure Defender for Cloud?
28. What is AKS node pool?
29. How do you scale AKS clusters?
30. How do Helm charts work in AKS?
31. What is Azure Functions Consumption Plan?
32. What are Durable Functions in Azure?
33. How does Event Grid integrate with Logic Apps?
34. What is the difference between Event Hub and Service Bus?
35. How does Azure DevOps integrate with GitHub Actions?
36. What are YAML pipelines in Azure DevOps?
37. What are Deployment Groups?
38. What are Artifacts in Azure DevOps used for?
39. What is Azure Cognitive Search?
40. What are Prebuilt Models in Cognitive Services?
41. How does Azure Machine Learning handle model deployment?
42. What is Databricks Delta Lake?
43. How does Azure Data Factory perform ETL?
44. What is Azure Lighthouse?
45. How does Azure Arc help with hybrid management?
46. How does Site Recovery work for DR scenarios?
47. What is Database Migration Service (DMS)?
48. What is Azure Blueprints?
49. How does Cost Management + Billing work?
50. What is Azure Pricing Calculator?

---

Advanced Level

1. How to design a hub-and-spoke network topology in Azure?
2. How does Azure Firewall work?
3. Difference between Firewall and NSG.
4. How do you design a global VNet architecture?
5. How to implement ExpressRoute Global Reach?
6. How does Azure Traffic Manager work?
7. How do you configure load balancing across regions?
8. How does Cosmos DB scale elastically?
9. How to tune indexing policies in Cosmos DB?
10. How to design for strong consistency vs eventual consistency?
11. How to optimize Synapse pipelines for big data?
12. How to integrate Synapse with Power BI?
13. How does Data Lake Gen2 handle hierarchical namespace?
14. How to secure storage accounts with Private Endpoints?
15. How to rotate keys in Key Vault automatically?
16. How to implement Conditional Access policies for external users?
17. How does Azure Sentinel integrate with Security Center?
18. How to configure Just-In-Time (JIT) access to VMs?
19. How to enforce least privilege in RBAC at scale?
20. How to configure Azure Policy for compliance enforcement?
21. How to deploy multi-region AKS clusters?
22. How to secure AKS clusters using Azure AD integration?
23. How to configure network policies in AKS?
24. How does Azure Functions integrate with VNETs?
25. How to optimize cold start in Functions?
26. What is an Event-driven serverless architecture with Event Grid?
27. How does Durable Functions support fan-out/fan-in?
28. How to design enterprise DevOps pipelines in Azure?
29. How to implement approvals in multi-stage pipelines?
30. How to use service connections securely in Azure DevOps?
31. How does Azure ML pipeline work?
32. How to monitor ML models in production with Azure Monitor?
33. How to scale Databricks clusters dynamically?
34. How to optimize Data Factory performance for large ETL jobs?
35. How to configure monitoring with Application Insights at scale?
36. How to use Azure Blueprints for governance?
37. How to implement hybrid Kubernetes clusters with Azure Arc?
38. How does Lighthouse manage multiple tenants?
39. How to configure advanced disaster recovery with Site Recovery?
40. How to migrate enterprise SAP workloads to Azure?
41. How to integrate Azure AD with on-prem Active Directory?
42. How to implement passwordless authentication in Azure?
43. How to use Azure Privileged Identity Management at scale?
44. How to handle data residency and compliance in Azure?
45. How to secure multi-cloud with Azure Security Center?
46. How to enforce compliance using Azure Defender?
47. How to design FinOps practices in Azure?
48. How to implement tagging governance?
49. How to use Managed Grafana in Azure Monitor?
50. How to implement custom log ingestion into Log Analytics?

---

Expert Level

1. How to design enterprise-scale landing zones in Azure?
2. How to enforce governance using Azure Policy at enterprise scale?
3. How to design Zero Trust architecture in Azure?
4. How to implement enterprise-wide RBAC strategy?
5. How to secure multi-tenant SaaS applications in Azure?
6. How to manage hybrid cloud with Azure Arc across multiple clouds?
7. How to configure cross-region traffic routing with Traffic Manager + Front Door?
8. How to implement Azure ExpressRoute with MPLS?
9. How to integrate Azure Stack with on-prem data centers?
10. How to manage sovereignty and compliance with Azure Government cloud?
11. How to secure highly regulated workloads (HIPAA, GDPR) in Azure?
12. How to design Cosmos DB for financial-grade workloads?
13. How to implement multi-master replication in Cosmos DB?
14. How to optimize Synapse Analytics for enterprise data warehouses?
15. How to implement Data Mesh with Azure Data Lake + Synapse?
16. How to implement cross-region failover with Azure SQL Hyperscale?
17. How to optimize ML lifecycle with MLOps in Azure?
18. How to integrate Databricks with Synapse for real-time analytics?
19. How to implement advanced data governance in Azure Purview?
20. How to build enterprise-scale IoT solutions with Azure IoT Hub?
21. How to integrate IoT Hub with Event Grid and Stream Analytics?
22. How to secure IoT devices with Azure Defender for IoT?
23. How to build digital twins using Azure Digital Twins?
24. How to implement edge computing with Azure IoT Edge?
25. How to build 5G-enabled solutions with Azure Private MEC?
26. How to integrate Azure with AWS and GCP in a multi-cloud strategy?
27. How to manage cost governance across multi-cloud with Azure Cost Management?
28. How to use Lighthouse for managed service providers (MSPs)?
29. How to enforce enterprise-wide tagging compliance?
30. How to implement chaos engineering in Azure?
31. How to implement automated incident response with Logic Apps?
32. How to build self-healing systems with Azure Monitor + Automation?
33. How to design HA/DR for SAP on Azure?
34. How to secure Kubernetes workloads across multi-region AKS?
35. How to implement service mesh (Istio/Linkerd) in AKS?
36. How to secure CI/CD pipelines with Azure DevOps + Key Vault?
37. How to implement GitOps in AKS using Flux/ArgoCD?
38. How to implement enterprise blockchain solutions with Azure Blockchain Service?
39. How to design HPC clusters in Azure for research workloads?
40. How to optimize large-scale video streaming with Azure Media Services?
41. How to design AI at scale using Azure Cognitive Services?
42. How to build enterprise knowledge mining solutions with Cognitive Search?
43. How to integrate Azure Synapse with Power Platform at scale?
44. How to secure enterprise ML pipelines with Responsible AI?
45. How to use Azure Arc-enabled Kubernetes for hybrid governance?
46. How to implement DevSecOps pipelines in Azure?
47. How to enforce compliance with Azure Policy + Defender across 1000+ subscriptions?
48. How to implement disaster recovery for multi-cloud apps?
49. How to run confidential computing workloads with Azure Confidential VMs?
50. How to architect for 99.999% availability on Azure?

Related Topics

Azure_DevOps

#GraphQL

Last updated    - V6 (03-Oct-2025)

Key Concepts

Topic	SubTopic	Basic ✅	Intermediate ✅	Advanced ✅	Expert ✅
Introduction	What is GraphQL, Features, Benefits, Use cases	✅	✅	✅	✅
GraphQL vs REST	Differences, Advantages, Limitations, When to use	✅	✅	✅	✅
Queries	Basics, Nested queries, Arguments, Aliases	✅	✅	✅	✅
Mutations	Create, Update, Delete operations, Input types	✅	✅	✅	✅
Subscriptions	Real-time updates, WebSockets, Implementation		✅	✅	✅
Schema	Types, Fields, Query type, Mutation type, Subscription type	✅	✅	✅	✅
Types	Scalar types, Object types, Enum, Interface, Union	✅	✅	✅	✅
Resolvers	Resolver functions, Arguments, Context, Parent object	✅	✅	✅	✅
Variables	Input variables, Default values, Variable types	✅	✅	✅	✅
Directives	@include, @skip, @deprecated, Custom directives	✅	✅	✅	✅
Error Handling	GraphQL errors, Error codes, Custom errors		✅	✅	✅
Authentication & Authorization	JWT, OAuth, Role-based access, Field-level security		✅	✅	✅
Performance Optimization	Query batching, Caching, DataLoader, Complexity analysis			✅	✅
Tooling & Ecosystem	Apollo, Relay, GraphiQL, GraphQL Playground	✅	✅	✅	✅
Best Practices	Schema design, Versioning, Pagination, Security	✅	✅	✅	✅

Interview question

Basic

1. What is GraphQL?
2. Who developed GraphQL?
3. What are the main benefits of GraphQL over REST?
4. What is a GraphQL schema?
5. What are queries in GraphQL?
6. What are mutations in GraphQL?
7. What are subscriptions in GraphQL?
8. What is a resolver in GraphQL?
9. What is the difference between query and mutation?
10. What are GraphQL types?
11. What are scalar types in GraphQL?
12. What are enums in GraphQL?
13. What are lists in GraphQL?
14. What are non-null types in GraphQL?
15. What is introspection in GraphQL?
16. What is a fragment in GraphQL?
17. What are directives in GraphQL?
18. What is the default HTTP method for GraphQL requests?
19. How is GraphQL strongly typed?
20. What is the difference between GraphQL and SQL?
21. Can GraphQL work without a database?
22. What is the role of __typename in GraphQL?
23. What is batching in GraphQL?
24. What is the purpose of GraphQL variables?
25. What are the limitations of GraphQL?

---

Intermediate

1. What is the role of GraphQL schema definition language (SDL)?
2. How do you define custom scalar types in GraphQL?
3. Explain input types in GraphQL.
4. What are unions in GraphQL?
5. What are interfaces in GraphQL?
6. How do you validate GraphQL queries?
7. How does GraphQL handle versioning?
8. What are the best practices for naming in GraphQL schema?
9. What is query complexity analysis?
10. How does GraphQL handle over-fetching and under-fetching?
11. What are nested resolvers?
12. What is the N+1 problem in GraphQL?
13. How can you solve the N+1 problem in GraphQL?
14. What is DataLoader in GraphQL?
15. How does GraphQL handle error reporting?
16. What are partial responses in GraphQL?
17. How does GraphQL differ from gRPC?
18. How do you use variables with fragments in GraphQL?
19. How does caching work in GraphQL?
20. What is persisted queries in GraphQL?
21. What is GraphQL Playground?
22. What is Apollo Server?
23. What is Relay in GraphQL?
24. How do GraphQL subscriptions work with WebSockets?
25. What are the security concerns in GraphQL?

---

Advanced

1. What are GraphQL Federation and schema stitching?
2. What is Apollo Federation?
3. What is the difference between schema stitching and federation?
4. What is GraphQL Gateway?
5. How do you implement authentication in GraphQL?
6. How do you implement authorization in GraphQL?
7. What are GraphQL directives and how do you create custom ones?
8. How do you handle file uploads in GraphQL?
9. What is GraphQL mesh?
10. What are GraphQL unions vs interfaces?
11. How do you implement batching in GraphQL resolvers?
12. What are best practices for designing GraphQL mutations?
13. How do you handle pagination in GraphQL?
14. What are Relay-style pagination and connections?
15. How do you handle rate limiting in GraphQL APIs?
16. What is query depth limiting in GraphQL?
17. How does GraphQL handle subscriptions at scale?
18. How does GraphQL integrate with microservices?
19. How do you monitor GraphQL performance?
20. How do you trace GraphQL queries in production?
21. What is schema federation in Apollo?
22. What are schema delegation techniques in GraphQL?
23. How do you modularize large GraphQL schemas?
24. What is GraphQL schema stitching middleware?
25. What are GraphQL schema directives for logging and tracing?

---

Expert

1. How do you secure GraphQL APIs against DoS attacks?
2. What is query cost analysis in GraphQL?
3. How do you handle caching in GraphQL at scale?
4. How do you integrate GraphQL with REST APIs?
5. How do you integrate GraphQL with gRPC?
6. How do you optimize GraphQL queries in production?
7. What are advanced DataLoader patterns?
8. How do you implement GraphQL schema federation in microservices architecture?
9. How do you version GraphQL schemas in large organizations?
10. How does GraphQL fit into Event-Driven Architectures (EDA)?
11. How do you monitor and log GraphQL errors?
12. How do you integrate GraphQL with Kafka?
13. How do you handle real-time updates in GraphQL at scale?
14. What is Apollo Gateway architecture?
15. How do you build resilient GraphQL APIs?
16. What are GraphQL SDL limitations and solutions?
17. How do you implement GraphQL authorization at field level?
18. How do you manage breaking changes in GraphQL APIs?
19. What are GraphQL best practices for microfrontends?
20. How do you design GraphQL APIs for large-scale enterprise systems?
21. What is GraphQL-over-HTTP vs GraphQL-over-WebSockets?
22. How do you handle federation across multiple teams in GraphQL?
23. What are common GraphQL anti-patterns?
24. What is the future of GraphQL in API design?
25. Compare GraphQL, REST, gRPC, and OData for enterprise use cases.

Related Topics

#SonarQube

Last updated    - V4 (16-Sep-2025)

Category	Topic	Sub-Topics (comma separated)	Basic	Intermediate	Advanced	Expert
Fundamentals	SonarQube Basics	Introduction, Features, Benefits, Terminology (Issues, Rules, Quality Gate)	✅
Fundamentals	Architecture	Components, Scanner, Server, Database, ElasticSearch, Web UI	✅	✅
Installation & Setup	Installation	System Requirements, Installing SonarQube, Configuring Database, Running on Localhost	✅	✅
Installation & Setup	Configuration	Global Settings, Project Settings, Database Setup, System Properties		✅	✅	✅
User Management	Authentication	Users, Groups, Roles, Permissions, Built-in Authentication	✅	✅
User Management	Integration	LDAP, SAML, Single Sign-On, External Identity Providers		✅	✅	✅
Project Analysis	Code Analysis	Static Code Analysis, Language Support, Analyzers, Rule Categories	✅	✅	✅	✅
Project Analysis	SonarQube Scanner	CLI Scanner, Maven Scanner, Gradle Scanner, MSBuild Scanner		✅	✅	✅
Project Analysis	Branch & PR Analysis	Feature Branch Analysis, Pull Request Decoration, Quality Gates in PRs		✅	✅	✅
Rules & Quality	Rules & Profiles	Rules, Quality Profiles, Inheritance, Custom Rules		✅	✅	✅
Rules & Quality	Quality Gates	Definition, Customization, Conditions, Enforcement	✅	✅	✅	✅
Metrics & Reporting	Metrics	Code Coverage, Duplications, Code Smells, Technical Debt, Maintainability Index	✅	✅	✅	✅
Metrics & Reporting	Reports	Project Reports, Portfolio Reports, Executive Dashboards		✅	✅	✅
Security	Vulnerability Detection	OWASP Top 10, Security Hotspots, Vulnerabilities, Security Reports		✅	✅	✅
Security	Compliance	GDPR, HIPAA, PCI-DSS, Custom Compliance Rules			✅	✅
Integrations	CI/CD Tools	Jenkins, GitHub Actions, GitLab CI/CD, Azure DevOps, Bitbucket Pipelines		✅	✅	✅
Integrations	IDE Integration	SonarLint (IntelliJ, Eclipse, VS Code), Local Analysis, Synchronization	✅	✅	✅	✅
Database & Storage	Database Management	PostgreSQL, MySQL, Database Configuration, Backup & Restore		✅	✅	✅
Customization & Extensibility	Custom Rules	Extending Rules, Writing Custom Plugins, Java-based Rule Development			✅	✅
Customization & Extensibility	API & Webhooks	Web API, REST API Usage, Webhooks Integration, Automation			✅	✅
Advanced Usage	Multi-Language Support	Java, Python, JavaScript, C#, C/C++, PHP, Go	✅	✅	✅	✅
Advanced Usage	Performance & Scaling	Large Instance Management, High Availability, Horizontal Scaling, Cluster Setup			✅	✅
Administration	Monitoring	System Health, Logs, Performance Monitoring, Alerts	✅	✅	✅	✅
Administration	Maintenance	Upgrading SonarQube, Plugin Management, Backup & Restore, Troubleshooting		✅	✅	✅

🟢 Basic Level

Fundamentals

1. What is SonarQube, and why is it used?
2. Explain the difference between SonarQube and SonarLint.
3. What are the main features of SonarQube?
4. Define the terms: Code Smells, Vulnerabilities, Bugs.
5. What is a Quality Gate in SonarQube?
6. Which languages are supported by SonarQube?
7. How does SonarQube perform static code analysis?
8. What is the role of the SonarQube server?
9. What is a Quality Profile?
10. Can SonarQube check coding standards?

Installation & Setup

1. What are the prerequisites for installing SonarQube?
2. Which database does SonarQube commonly use?
3. How do you install SonarQube on Windows?
4. How do you start SonarQube after installation?
5. What is the default port used by SonarQube?
6. What is the role of Elasticsearch in SonarQube?
7. Can SonarQube run without a database?
8. What is the default username and password of SonarQube?
9. How do you install SonarQube plugins?
10. What is the function of sonar-scanner?

Project Configuration

1. How do you add a new project in SonarQube?
2. What are the basic project settings available in SonarQube?
3. How can you run analysis on a Java project?
4. Which file is used for SonarQube project properties?
5. How can you configure project exclusions?

User Management

1. How do you create a new user in SonarQube?
2. What are the default roles available?
3. How do you assign permissions to a group?
4. What is the difference between global and project-level permissions?
5. Can LDAP authentication be integrated in SonarQube Basic edition?

Reports & Metrics

1. What metrics does SonarQube collect by default?
2. What is code coverage in SonarQube?
3. How does SonarQube measure technical debt?
4. What is the purpose of duplications metric?
5. What is Maintainability Index?

General

1. What is SonarLint, and how does it integrate with IDEs?
2. Explain ?Hotspot? in SonarQube.
3. What is the default admin account in SonarQube?
4. Which type of testing does SonarQube support directly?
5. Does SonarQube check runtime errors?

Miscellaneous

1. What are the licensing models of SonarQube?
2. How do you enable email notifications?
3. How can you reset the admin password in SonarQube?
4. Can SonarQube analyze pull requests in the community edition?
5. What is the role of SonarCloud?
6. How do you uninstall SonarQube?
7. Which command is used to run sonar-scanner?
8. How do you restart SonarQube from CLI?
9. Can SonarQube analyze open-source projects for free?
10. What is the default database schema name for SonarQube?

---

🟡 Intermediate Level

Architecture & Configuration

1. Explain SonarQube architecture.
2. What are the roles of SonarQube components (Web, Compute, Elastic)?
3. How does SonarQube integrate with build tools (Maven/Gradle)?
4. How do you configure SonarQube with Jenkins?
5. What is the use of sonar-project.properties file?
6. Explain branch analysis in SonarQube.
7. How does SonarQube handle PR decoration?
8. What is the difference between global settings and project settings?
9. How do you enable debugging logs in SonarQube?
10. What are Quality Profiles, and how do you apply them?

Code Analysis

1. How do you exclude files/folders from analysis?
2. What are SonarQube plugins, and name a few important ones?
3. Explain the difference between SonarScanner CLI and Maven scanner.
4. How do you configure SonarQube for multiple languages?
5. Can SonarQube detect duplicated code across projects?

Security

1. How are vulnerabilities classified in SonarQube?
2. What is the difference between vulnerabilities and hotspots?
3. How do you enforce authentication in SonarQube?
4. How do you set up LDAP authentication?
5. Can SonarQube encrypt database credentials?

CI/CD Integrations

1. How do you integrate SonarQube with GitHub Actions?
2. What is PR decoration, and how is it set up?
3. How do you configure SonarQube with GitLab CI?
4. How can Bitbucket Pipelines be used with SonarQube?
5. Can Azure DevOps integrate with SonarQube?

Reports & Metrics

1. What is the difference between Bugs and Code Smells?
2. What are duplications, and how are they measured?
3. How do you track coverage trends in SonarQube?
4. What is a Security Report in SonarQube?
5. What is the technical debt ratio?

User Management

1. How do you create custom roles in SonarQube?
2. How do you restrict access to a specific project?
3. Explain permission templates.
4. What are the limitations of the community edition in access control?
5. How do you enable SAML-based authentication?

Maintenance

1. How do you upgrade SonarQube safely?
2. What are the steps to back up SonarQube data?
3. How do you monitor SonarQube performance?
4. Which logs are generated by SonarQube?
5. How do you restore a failed SonarQube instance?

Miscellaneous

1. What is the difference between SonarQube Community and Developer edition?
2. How do you schedule automatic analysis?
3. Can SonarQube integrate with Docker-based builds?
4. How do you troubleshoot ?Compute Engine is down? error?
5. What is ?ElasticSearch yellow status? in SonarQube?
6. How do you run analysis on a legacy project?
7. Can SonarQube detect secrets in source code?
8. How do you enable custom dashboards?
9. How do you manage rule inheritance?
10. What is the maximum number of projects supported in Community edition?

---

🔵 Advanced Level

Architecture & Scaling

1. How do you set up SonarQube for enterprise-scale use?
2. What is SonarQube clustering?
3. How do you configure SonarQube for high availability?
4. What are the compute engine workers in SonarQube?
5. How do you tune JVM settings for SonarQube?

Rules & Quality Profiles

1. How do you create custom rules in SonarQube?
2. Can you extend existing rule sets?
3. How do you export/import Quality Profiles?
4. How do you enforce a specific Quality Gate across all projects?
5. How do you set custom thresholds in Quality Gates?

Customization & Extensibility

1. How do you write a custom plugin in SonarQube?
2. What is the role of Java APIs in custom rule development?
3. How do you automate rule enforcement using APIs?
4. How do you extend SonarQube with external tools?
5. How do you integrate SonarQube with third-party dashboards?

Security

1. How do you detect OWASP Top 10 vulnerabilities with SonarQube?
2. Can SonarQube integrate with dependency checkers?
3. How do you enforce secure coding practices using SonarQube?
4. How do you configure Security Hotspot review workflow?
5. Can SonarQube detect SQL injection vulnerabilities?

Advanced Integrations

1. How do you configure SonarQube with multi-branch Jenkins pipelines?
2. How do you integrate SonarQube with Terraform or Ansible?
3. Can SonarQube be used in GitOps workflows?
4. How do you set up automated pull request decoration for all repos?
5. How do you integrate SonarQube with Slack/MS Teams notifications?

Performance & Monitoring

1. How do you monitor SonarQube with Prometheus/Grafana?
2. How do you optimize database performance in SonarQube?
3. How do you handle SonarQube for large monorepos?
4. How do you clean old analysis data?
5. What is the role of housekeeping in SonarQube?

Maintenance

1. How do you upgrade SonarQube plugins?
2. What steps should be taken before a major version upgrade?
3. How do you configure disaster recovery for SonarQube?
4. How do you manage downtime during upgrade?
5. How do you troubleshoot analysis timeouts?

Miscellaneous

1. How does SonarQube calculate maintainability rating?
2. Can you enforce 100% code coverage using Quality Gates?
3. How do you extend SonarQube APIs for automation?
4. What is the difference between Portfolio and Project dashboards?
5. Can SonarQube integrate with containerized builds in Kubernetes?
6. How do you migrate SonarQube to a new database server?
7. How do you clean up inactive users/projects automatically?
8. What is the maximum number of concurrent scans supported?
9. Can SonarQube be used with multi-language microservices?
10. How do you apply code analysis to only changed files?
11. What are the limitations of SonarQube in detecting runtime issues?
12. How do you configure API tokens securely?
13. What are the common performance bottlenecks in SonarQube?
14. How do you troubleshoot SonarQube web API errors?
15. Can SonarQube be deployed in serverless environments?

---

🔴 Expert Level

Enterprise & Governance

1. How do you set up SonarQube in a large-scale enterprise environment?
2. What are the governance features in SonarQube Enterprise edition?
3. How do you manage portfolios and applications in SonarQube?
4. What is SonarQube Data Center Edition?
5. How do you implement enterprise-wide Quality Gates?

Scaling & High Availability

1. How do you configure SonarQube clustering with multiple nodes?
2. How do you distribute compute engine tasks across servers?
3. What are best practices for high availability?
4. How do you ensure zero-downtime upgrades?
5. How do you benchmark SonarQube performance at scale?

Security & Compliance

1. How do you map SonarQube issues to regulatory frameworks (e.g., GDPR, HIPAA)?
2. How do you configure SonarQube for PCI-DSS compliance?
3. Can SonarQube integrate with SAST/DAST tools?
4. How do you create compliance dashboards in SonarQube?
5. How do you enforce enterprise security standards with SonarQube?

Advanced Customization

1. How do you develop a fully custom SonarQube plugin?
2. How do you extend SonarQube rules using AST parsing?
3. Can SonarQube integrate with AI-based code review tools?
4. How do you build custom dashboards using the SonarQube API?
5. How do you integrate SonarQube with data lakes or BI tools?

DevOps & Automation

1. How do you run SonarQube in a Kubernetes cluster with autoscaling?
2. How do you integrate SonarQube with GitOps pipelines?
3. How do you enforce SonarQube checks as mandatory in CI/CD?
4. How do you configure SonarQube for multi-tenant DevOps teams?
5. How do you secure SonarQube tokens in CI/CD pipelines?

Performance Optimization

1. What are strategies for scaling SonarQube for 10,000+ projects?
2. How do you optimize analysis speed for very large repositories?
3. How do you configure SonarQube for distributed analysis?
4. How do you set up caching for sonar-scanner?
5. What are best practices for JVM and DB tuning in SonarQube enterprise setups?

Enterprise Reporting

1. How do you create executive-level compliance reports?
2. What is the difference between Portfolios and Applications in SonarQube?
3. How do you automate report generation for stakeholders?
4. How do you integrate SonarQube reports with Jira or ServiceNow?
5. How do you track KPIs across multiple business units?

Miscellaneous Expert

1. How do you migrate SonarQube from on-premise to SonarCloud?
2. How do you integrate SonarQube with enterprise SSO systems?
3. What are the risks of misconfigured Quality Gates at enterprise scale?
4. How do you monitor SonarQube logs in centralized logging systems (ELK/Splunk)?
5. How do you implement fine-grained access control across 1000+ users?
6. How do you create custom compliance rules for a specific industry?
7. How do you handle multi-language monorepos in SonarQube?
8. How do you perform enterprise-level backup and recovery testing?
9. How do you design SonarQube architecture for hybrid cloud environments?
10. What are SonarQube?s limitations compared to commercial SAST tools?
11. How do you integrate SonarQube with AI-based bug prediction models?
12. How do you implement cost optimization in cloud-based SonarQube setups?
13. How do you extend SonarQube with GraphQL APIs?
14. How do you design automated remediation workflows from SonarQube findings?
15. What are the future trends in SonarQube and code quality management?

---

#Shell Scripts

Question count - 0     Last updated    - V2 (18-Nov-2023)

What is a shell?

What is shell scripts?

What are the benefits of using shell scripting?

What is the base of the Unix shell?

What is the average lifespan of a variable in the shell?

What are the security provisions provided by the Unix to protect the system?

What are the top three significant editors in Unix?

What is the alternative command for the echo?

What IFS denotes in the shell?

What is break statement why do we use it?

Write down the types of shell variables?

Write down modes of operations in Vi editors and describe them?

Explain the difference between soft and hard links?

Which command you will use to find out the run time?

How do you create shortcuts in the Linux?

How do you know if you have the soft or hard link?

How hard links are used in the UNIX?

How will you find out which command you are currently using?

How you can completely remove variables from the shell?

Who wrote the first UNIX shell in history?

#Hibernate

Last updated    - V6 (03-Oct-2025)

Key Concepts

Level	Topic	Subtopics
Basic	Introduction	What is Hibernate, Features of Hibernate, ORM Concepts, Hibernate Architecture, Advantages of Hibernate
	Setup & Configuration	Installing Hibernate, Hibernate Dependencies, Hibernate Configuration Files, Hibernate Properties, Annotation vs XML configuration
	Basic CRUD Operations	Session, Transaction, Save(), Persist(), Update(), Delete(), Get(), Load(), SessionFactory
	Hibernate Data Types	Primitive Types, Wrapper Types, Date & Time Types, Collections, Custom Types
	Hibernate Mappings	Mapping Classes to Tables, Mapping Attributes to Columns, @Entity, @Table, @Column, @Id
Intermediate	Associations & Relationships	One-to-One, One-to-Many, Many-to-One, Many-to-Many, Mapping Annotations, Cascade Types, Fetch Types, JoinTable, JoinColumn
	Hibernate Query Language (HQL)	Introduction to HQL, HQL Syntax, HQL Select Queries, HQL Update/Delete, Named Queries, Aggregate Functions
	Criteria API	Creating Criteria, Restrictions, Projections, Logical Expressions, Ordering, Pagination
	Hibernate Caching	First-Level Cache, Second-Level Cache, Query Cache, Cache Providers, Cache Annotations
	Inheritance Mapping	Single Table Strategy, Joined Table Strategy, Table per Class Strategy, @Inheritance, @DiscriminatorColumn
Advanced	Transactions & Concurrency	ACID Concepts, Transaction Management, Optimistic Locking, Pessimistic Locking, Versioning, @Version Annotation
	Fetching Strategies	Eager vs Lazy Loading, N+1 Problem, Batch Fetching, FetchMode, @Fetch Annotation
	Hibernate Events & Listeners	Event Types, PreInsert, PostInsert, PreUpdate, PostUpdate, PreDelete, PostDelete, Event Listeners
	Hibernate Interceptors	Implementing Interceptors, onSave(), onDelete(), onLoad(), Custom Interceptors
	Advanced HQL & Native Queries	HQL Joins, Subqueries, Group By, Having, Named Native Queries, SQLQuery API
Expert	Performance Tuning	Optimizing Session Usage, Batch Processing, Lazy Loading Best Practices, Fetch Joins, Indexing, Query Optimization
	Hibernate Search	Integrating Hibernate Search, Lucene, Full-Text Search, Indexing Entities, Querying Index
	Multi-Tenancy	Database Multi-Tenancy, Schema Multi-Tenancy, Discriminator Multi-Tenancy, Configuration
	Advanced Caching Techniques	Custom Cache Regions, Cache Concurrency Strategies, Read-Only, Non-Strict Read-Write, Transactional Cache
	Best Practices & Design Patterns	Session Management, DAO Pattern, Repository Pattern, Open Session In View Pattern, Avoiding Common Pitfalls

Interview question

1. Hibernate Basics

1. What is Hibernate and why is it used?
2. Explain ORM (Object-Relational Mapping) concept.
3. What are the main features of Hibernate?
4. Difference between Hibernate and JDBC.
5. Explain Hibernate architecture.
6. What is SessionFactory in Hibernate?
7. What is a Session in Hibernate?
8. Difference between get() and load() methods.
9. Explain Hibernate Query Language (HQL).
10. What are Hibernate annotations?
11. Difference between Hibernate XML configuration and annotation-based configuration.
12. Explain Hibernate?s advantages over JDBC.
13. What are persistent, detached, and transient objects?
14. Explain Hibernate?s first-level cache.
15. How do you configure Hibernate using hibernate.cfg.xml?
16. What is Hibernate mapping?
17. Difference between @Entity and @Table annotations.
18. Explain @Id and @GeneratedValue annotations.
19. How do you save an object using Hibernate?
20. How do you update an object using Hibernate?
21. How do you delete an object using Hibernate?
22. Difference between persist() and save() methods.
23. Difference between merge() and update() methods.
24. How do you handle exceptions in Hibernate?
25. Explain Hibernate?s lifecycle of an entity.

---

2. Hibernate Mappings & Relationships

1. Explain One-to-One mapping in Hibernate.
2. Explain One-to-Many mapping in Hibernate.
3. Explain Many-to-One mapping in Hibernate.
4. Explain Many-to-Many mapping in Hibernate.
5. Difference between unidirectional and bidirectional mapping.
6. How do you map collections in Hibernate?
7. Explain @JoinColumn annotation.
8. Explain @JoinTable annotation.
9. How do you handle composite keys in Hibernate?
10. What is @EmbeddedId and @Embeddable?
11. Difference between @ElementCollection and @CollectionTable.
12. How do you map inheritance in Hibernate?
13. Explain single-table inheritance strategy.
14. Explain joined-table inheritance strategy.
15. Explain table-per-class inheritance strategy.
16. What is @DiscriminatorColumn and @DiscriminatorValue?
17. Difference between eager and lazy fetching.
18. Explain @OneToMany(fetch=FetchType.LAZY).
19. Explain cascade types in Hibernate.
20. How do you implement orphan removal?
21. Difference between mappedBy and owning side in relationships.
22. How do you map a bidirectional Many-to-Many relationship?
23. How do you handle self-referencing associations?
24. How do you handle join fetch to avoid N+1 problem?
25. Best practices for Hibernate mappings.

---

3. Hibernate Queries

1. What is HQL and how is it different from SQL?
2. How do you write basic HQL queries?
3. How do you write HQL update queries?
4. How do you write HQL delete queries?
5. Explain named queries in Hibernate.
6. Difference between named query and native query.
7. How do you pass parameters in HQL?
8. How do you use positional and named parameters?
9. Explain criteria API in Hibernate.
10. Difference between criteria and HQL.
11. How do you add restrictions in criteria queries?
12. How do you use projections in criteria queries?
13. How do you implement pagination in HQL and criteria queries?
14. Explain aggregate functions in HQL.
15. How do you perform joins in HQL?
16. How do you implement subqueries in HQL?
17. How do you use group by and having in HQL?
18. Difference between fetch join and normal join.
19. How do you execute native SQL queries in Hibernate?
20. Difference between executeUpdate() and getResultList().
21. How do you map query results to DTOs?
22. How do you handle dynamic queries in Hibernate?
23. What is query caching in Hibernate?
24. How do you optimize HQL queries?
25. Best practices for Hibernate queries.

---

4. Hibernate Transactions & Concurrency

1. What is a transaction in Hibernate?
2. How do you begin and commit a transaction?
3. Difference between transaction and session in Hibernate.
4. How do you handle rollback in Hibernate?
5. Explain ACID properties in the context of Hibernate.
6. Difference between optimistic and pessimistic locking.
7. How do you implement versioning in Hibernate?
8. Explain @Version annotation.
9. How do you handle concurrent updates in Hibernate?
10. Difference between optimistic and pessimistic concurrency control.
11. How do you use LockMode in Hibernate?
12. Difference between transaction-scoped and session-scoped transactions.
13. How do you integrate Hibernate with JTA?
14. Difference between programmatic and declarative transactions.
15. How do you handle nested transactions in Hibernate?
16. How do you use Spring transaction management with Hibernate?
17. Difference between read-only and read-write transactions.
18. How do you handle long-running transactions?
19. How do you implement rollback rules in Spring + Hibernate?
20. How do you manage isolation levels in Hibernate?
21. Difference between transaction propagation behaviors.
22. How do you test transaction behavior in Hibernate?
23. How do you prevent lost updates in Hibernate?
24. How do you handle deadlocks in Hibernate transactions?
25. Best practices for transaction management.

---

5. Hibernate Caching

1. What is caching in Hibernate?
2. Difference between first-level cache and second-level cache.
3. Explain session cache in Hibernate.
4. How do you enable second-level cache?
5. What are cache providers in Hibernate?
6. Explain query cache in Hibernate.
7. Difference between query cache and second-level cache.
8. How do you configure cache concurrency strategies?
9. What is read-only cache strategy?
10. What is read-write cache strategy?
11. Explain non-strict read-write cache.
12. Difference between transactional cache and non-transactional cache.
13. How do you evict cache entries manually?
14. How do you clear session cache?
15. How do you use @Cache annotation?
16. How do you integrate EHCache with Hibernate?
17. How do you integrate Infinispan with Hibernate?
18. How do you handle cache invalidation?
19. How do you monitor cache performance?
20. How do you optimize caching in Hibernate?
21. Difference between collection caching and entity caching.
22. How do you use natural IDs with caching?
23. How do you enable caching for read-only entities?
24. How do you configure cache regions?
25. Best practices for Hibernate caching.

---

6. Hibernate Events & Interceptors

1. What are Hibernate events?
2. Difference between events and interceptors.
3. What are pre-insert and post-insert events?
4. What are pre-update and post-update events?
5. What are pre-delete and post-delete events?
6. How do you implement event listeners in Hibernate?
7. How do you register event listeners?
8. Explain lifecycle callbacks in Hibernate.
9. What is Hibernate Interceptor?
10. How do you implement onSave() in an interceptor?
11. How do you implement onDelete() in an interceptor?
12. How do you implement onLoad() in an interceptor?
13. How do you implement onFlushDirty() in an interceptor?
14. Difference between session-scoped and global interceptors.
15. How do interceptors affect performance?
16. How do you use interceptors with JPA?
17. How do you debug Hibernate events?
18. Difference between pre-commit and post-commit events.
19. How do you prevent unwanted event execution?
20. How do you chain multiple interceptors?
21. Difference between EntityListeners and Hibernate events.
22. How do you implement auditing using events?
23. How do you implement logging using interceptors?
24. How do you test events and interceptors?
25. Best practices for Hibernate events and interceptors.

---

7. Advanced Hibernate Concepts

1. How do you implement batch processing in Hibernate?
2. What is StatelessSession in Hibernate?
3. Difference between Session and StatelessSession.
4. How do you handle large data sets efficiently?
5. What is multi-tenancy in Hibernate?
6. Explain database multi-tenancy strategy.
7. Explain schema multi-tenancy strategy.
8. Explain discriminator multi-tenancy strategy.
9. How do you implement auditing in Hibernate?
10. How do you integrate Hibernate Envers?
11. How do you handle soft deletes?
12. How do you implement full-text search with Hibernate Search?
13. How do you integrate Hibernate Search with Lucene?
14. How do you implement projections and aggregations?
15. How do you use Criteria API for complex queries?
16. How do you handle native SQL queries?
17. Difference between SQLQuery and NativeQuery.
18. How do you map complex results to DTOs?
19. How do you handle dynamic entity models?
20. How do you optimize Hibernate performance?
21. How do you monitor Hibernate SQL queries?
22. How do you use logging frameworks with Hibernate?
23. How do you implement custom types in Hibernate?
24. How do you implement secondary tables for entities?
25. Best practices for advanced Hibernate concepts.

Related Topics

#Apache_Spark

Last updated    - V6 (17-Sep-2025)

Key Concepts

Topic	Sub-Topics	Basic	Intermediate	Advanced	Expert
Introduction	What is Spark, Features, Spark vs Hadoop, Use cases	✅	✅
Architecture	Spark Components, Driver, Executor, Cluster Manager, DAG, Jobs, Stages, Tasks	✅	✅	✅	✅
RDDs	Resilient Distributed Datasets, Transformations, Actions, Caching, Persistence	✅	✅	✅	✅
DataFrames & Datasets	Creation, Schema, Operations, Optimizations, Catalyst Engine	✅	✅	✅	✅
Spark SQL	SQL Queries, Data Sources, Temporary Views, Performance Tuning	✅	✅	✅	✅
Spark Streaming	DStreams, Structured Streaming, Window Operations, Checkpointing	✅	✅	✅	✅
Spark MLlib	Machine Learning APIs, Pipelines, Models, Feature Engineering	✅	✅	✅	✅
Spark GraphX	Graphs, Pregel API, Graph Algorithms		✅	✅	✅
Spark Core APIs	RDD API, Transformations, Actions, Accumulators, Broadcast Variables	✅	✅	✅	✅
Performance Tuning	Partitioning, Caching, Shuffling, Join optimizations, Resource tuning		✅	✅	✅
Cluster Management	Standalone, YARN, Mesos, Kubernetes, Resource Allocation	✅	✅	✅	✅
Debugging & Monitoring	Spark UI, Logs, Event Timeline, Metrics, Executors monitoring	✅	✅	✅	✅
Fault Tolerance	Lineage, Task Retry, Checkpointing, Speculative Execution	✅	✅	✅	✅
Advanced Features	Custom Partitioner, User-defined functions, Structured Streaming triggers		✅	✅	✅
Integration	Hive, HDFS, Kafka, Cassandra, Parquet, ORC, JDBC	✅	✅	✅	✅

Interview question

1. Introduction & Basics

1. What is Apache Spark and what are its main features?
2. How does Spark differ from Hadoop MapReduce?
3. What are the core components of Spark?
4. What is SparkContext?
5. What is the role of a Driver in Spark?
6. What is an Executor in Spark?
7. What is a DAG in Spark?
8. What are jobs, stages, and tasks in Spark?
9. What are the key use cases of Spark?
10. What is the difference between batch processing and stream processing in Spark?

---

2. Architecture

1. Explain the Spark architecture.
2. What are the main cluster managers supported by Spark?
3. How does Spark schedule tasks?
4. How does Spark handle fault tolerance?
5. What is the role of the DAG scheduler?
6. How are RDDs distributed across the cluster?
7. How does Spark handle data locality?
8. What is the role of the Task Scheduler?
9. How does Spark communicate between Driver and Executors?
10. What is the Spark UI and how is it used?

---

3. RDDs

1. What is an RDD in Spark?
2. How do you create RDDs?
3. What are the main transformations in RDDs?
4. What are the main actions in RDDs?
5. How does Spark achieve fault tolerance in RDDs?
6. What is the difference between narrow and wide transformations?
7. How do caching and persistence work in RDDs?
8. What is a lineage graph?
9. What is the difference between map() and flatMap()?
10. How do you perform joins on RDDs?

---

4. DataFrames & Datasets

1. What is a DataFrame in Spark?
2. How do DataFrames differ from RDDs?
3. How do you create a DataFrame?
4. What are Datasets in Spark?
5. How do Datasets differ from DataFrames?
6. How does Spark infer schema automatically?
7. How do you perform filtering and aggregations on DataFrames?
8. What is the Catalyst optimizer?
9. How do you register a temporary view for SQL queries?
10. How do you handle missing data in DataFrames?

---

5. Spark SQL

1. How do you execute SQL queries in Spark?
2. How do you connect Spark to Hive?
3. What are the different data sources supported by Spark SQL?
4. How do you create external and managed tables?
5. What is partitioning in Spark SQL?
6. How do you optimize joins in Spark SQL?
7. How do you cache tables in Spark SQL?
8. How does Spark SQL handle schema evolution?
9. How do you use UDFs in Spark SQL?
10. How do you monitor query performance in Spark SQL?

---

6. Spark Streaming

1. What is Spark Streaming?
2. What are DStreams?
3. How does Structured Streaming differ from DStreams?
4. What are window operations in Spark Streaming?
5. What is checkpointing and why is it used?
6. How do you handle late data in streaming?
7. What are triggers in Structured Streaming?
8. How do you integrate Kafka with Spark Streaming?
9. How do you monitor streaming jobs?
10. How do you ensure exactly-once semantics in streaming?

---

7. Spark MLlib

1. What is MLlib?
2. What are the main features of MLlib?
3. How do you create a machine learning pipeline in Spark?
4. How do you handle feature engineering in Spark MLlib?
5. What are transformers and estimators?
6. How do you perform model evaluation?
7. How do you handle classification tasks in Spark MLlib?
8. How do you handle regression tasks?
9. How do you save and load models?
10. How do you tune hyperparameters in Spark MLlib?

---

8. Spark GraphX

1. What is GraphX?
2. How do you represent graphs in Spark?
3. What are vertices and edges?
4. What is the Pregel API?
5. How do you compute PageRank in GraphX?
6. How do you find connected components?
7. How do you implement graph algorithms using GraphX?
8. How do you persist graph data?
9. How do you visualize graphs from Spark?
10. What are practical use cases of GraphX?

---

9. Performance Tuning

1. How do you optimize partitioning in Spark?
2. How do you reduce shuffle operations?
3. How do you cache and persist data for performance?
4. How do you tune memory and executor configurations?
5. What are broadcast variables and how are they used?
6. How do accumulators work in Spark?
7. How do you optimize joins in Spark?
8. How do you handle skewed data?
9. How do you monitor and profile Spark jobs?
10. How do you use Tungsten optimization?

---

10. Cluster Management

1. What are the different deployment modes in Spark?
2. How do you run Spark in Standalone mode?
3. How do you run Spark on YARN?
4. How do you run Spark on Mesos?
5. How do you run Spark on Kubernetes?
6. How do you configure Spark executors and cores?
7. How do you handle dynamic allocation?
8. How do you manage resources in a multi-tenant cluster?
9. How do you submit a Spark job?
10. How do you handle failures in Spark clusters?

Related Topics