Interview Prep
This section aggregates the most important interview questions from each domain into dedicated per-domain Q&A pages. Each page organizes questions by difficulty (Beginner / Intermediate / Advanced) so you can focus revision time efficiently based on the role level you're targeting.
What You'll Find Here
| Domain | Focus Areas |
|---|---|
| Core Java Interview Q&A | Variables, operators, OOP, type system, String, Collections fundamentals. |
| OOP Interview Q&A | Classes, encapsulation, inheritance, polymorphism, abstraction, records, sealed classes. |
| Multithreading Interview Q&A | synchronized, volatile, CompletableFuture, virtual threads. |
| JVM Internals Interview Q&A | GC algorithms, class loading, JIT compilation, memory areas. |
| Functional Programming Q&A | Lambdas, Streams, method references, Optional. |
| Spring Framework Q&A | IoC, DI, AOP, bean scopes, bean lifecycle. |
| Spring Boot Q&A | Auto-configuration, starters, Actuator, profiles. |
| Spring Data Q&A | JPA mapping, transaction propagation, N+1 problem, @Transactional. |
| Spring Security Q&A | Filter chain, OAuth2 flows, JWT validation, method security. |
| System Design Q&A | Microservices trade-offs, caching, reliability patterns, API design. |
How to Use This Section
- Skim Beginner questions in each page to confirm you have no blind spots in the basics.
- Focus revision time on Intermediate questions — these are the target for 3–5 YOE roles.
- Work through Advanced questions to prepare for senior and staff engineer interviews.