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Overviews

Each overview page condenses an entire domain into a single scannable page: key concepts at a glance, a quick-reference API table, a suggested learning path, and the top 5 interview questions. Designed to be absorbed in under 10 minutes before an interview.

Domain Overview Pages

DomainWhat It Covers
Core Java OverviewVariables, type system, collections, streams, concurrency at a glance.
OOP OverviewClasses, encapsulation, inheritance, polymorphism, abstraction, records, sealed classes.
JVM OverviewMemory model, GC algorithms, class loading, JIT — tuning flags and diagnostics.
Spring Framework OverviewIoC, DI, AOP, bean lifecycle, scopes — key APIs and annotations.
Spring Boot OverviewAuto-configuration, starters, profiles, Actuator, testing slices.
Spring Data OverviewJPA annotations, repository methods, @Transactional propagation table.
Spring Security OverviewFilter chain, auth flow, OAuth2 flows, JWT structure.
Multithreading OverviewThread lifecycle, concurrency utilities, CompletableFuture cheat-table.
System Design OverviewSOLID, microservices trade-offs, caching, reliability patterns.

How to Use These Pages

  1. Use full domain notes for learning — these pages are NOT substitutes for the notes.
  2. Use overview pages for revision — scan them the day before an interview.
  3. Pair each overview with the matching Interview Prep Q&A page for complete coverage.
  • Interview Prep — per-domain Q&A pages that complement these overviews.
  • Java — the Java parent domain links to all language subdomains.