Every question you'll actually get asked
Java, Spring Boot, Microservices, Design Patterns, System Design, DevOps & AWS — organized by topic and difficulty. See what's actually being asked in one line, then let AI build the complete answer when you're ready to learn it.
What's inside
Java, Spring Boot & Microservices
Core Java, Collections, Multithreading, JVM internals, Spring Boot, JPA/Hibernate, transactions, and the microservice patterns — Saga, CQRS, resilience — that come up alongside them.
Design Patterns, LLD & System Design
Gang of Four patterns, SOLID applied to real code, machine-coding rounds like Parking Lot and Rate Limiter, plus HLD favorites — design TinyURL, WhatsApp, Uber, Netflix.
AI Builds the Answer, On Demand
Every question shows just a short teaser upfront. Click Generate and the AI builds a complete answer — background, theory, a real code example explained line by line, and how the question gets asked differently.
Free open questions
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Every question builds a complete answer on demand — no generic notes to skim past. Start with the free Core Java category — no account required to browse.