Cracking the Java Interview

Most interview prep hands you the definition. This hands you the answer that actually lands.

480 questions across 30 sections, each answered the way a senior engineer answers in the room — the mechanism, the trade-off, and the code. 397 pages, written from scratch.

What's inside

• Core Java — OOP, JVM internals, memory areas, garbage collection, exceptions, generics
• Collections — HashMap internals, fail-fast vs fail-safe, concurrent collections
• Java 8 — lambdas, streams, parallel streams and how they actually schedule, Optional
• Modern Java 9 → 25 — records, sealed types, pattern matching, virtual threads, structured concurrency, scoped values
• Concurrency — the Java Memory Model, happens-before, locks, executors, CompletableFuture
• Spring & Spring Boot 3 — IoC, AOP, auto-configuration, transactions, JPA, security
• Architecture — REST design, microservices patterns, messaging, resilience, observability, cloud-native
• Spring AI — RAG, embeddings, vector stores, Model Context Protocol
• Design patterns, build tools, testing — the rounds people forget to prepare for
• 20 predict-the-output puzzles — everyone compiled and verified on JDK 21

Why this one

• Answers go past the definition to the *why* — what breaks, what it costs, when not to reach for it
• Every code sample is real, compilable Java, syntax-highlighted
• Covers Java 25 LTS properly, not Java 8 wearing a modern coat of paint
• Written and edited from scratch

Who it's for

Java developers with 2–10 years of experience heading into product or service company interviews — and anyone who would rather have one reference than forty browser tabs.

What you get

• 397-page PDF, instant download after payment
• Lifetime access, plus free updates to this edition
• Reads on any device

First Edition · August 2026 · Ankush Kumar