Java
JavaBuild a Spring Boot CRUD App with a Database (Step by Step)
Build a complete Spring Boot CRUD application for products, backed by a database: entity, repository, service with a proper update, controller with all four operations, and testing.
JavaBuild a Spring Boot REST API Project (Step by Step)
Build a complete Spring Boot REST API project for managing tasks: entity, repository, service, and controller with full CRUD, plus how to test it and make it portfolio-ready.
JavaBuild a Java Console Project: A To-Do App (Step by Step)
Build your first real Java project: a menu-driven console To-Do app. Step by step with classes, ArrayList, Scanner input, and a clean menu loop — no frameworks needed.
JavaJava Projects for Beginners: Ideas from Console to Backend
A ladder of beginner-friendly Java project ideas to build real skills and a portfolio: console apps, OOP systems, and Spring Boot backends, with links to full build guides.
JavaDSA Interview Questions in Java (Patterns, Not Problems) — Freshers to Senior
A practical Java DSA interview guide organised by pattern: complexity fundamentals, a signal-to-pattern cheat-sheet, and worked template solutions for two sum, sliding window, cycle detection, top-K heap, DP memoisation, plus BFS/DFS, BST, sorting comparison, and a step-by-step problem-solving framework.
JavaSpring Boot Interview Questions (Auto-config, Proxies & @Transactional) — Freshers to Senior
A senior-level Spring Boot interview guide covering IoC/DI, constructor injection, bean lifecycle and scopes, auto-configuration internals with @Conditional, JDK vs CGLIB proxies, the @Transactional self-invocation trap, transaction propagation/rollback, N+1 queries, and configuration/profiles.
JavaJava Exception Handling Interview Questions (Traps & Best Practices) — Freshers to Senior
A senior-level Java exception-handling interview guide: the Throwable hierarchy, checked vs unchecked design decisions, try-with-resources and suppressed exceptions, finally traps, precise rethrow, exception chaining, checked exceptions with lambdas/streams, NPE avoidance, and best practices.
JavaJava Multithreading Interview Questions (JMM, Locks & Traps) — Freshers to Senior
A senior-level Java concurrency interview guide covering the Java Memory Model, visibility vs atomicity, volatile/synchronized/atomic, CAS, ReentrantLock, wait-notify, deadlock and coordination tools, ThreadPoolExecutor internals, CompletableFuture, double-checked locking, and Java 21 virtual threads.
JavaJava Collections Interview Questions (Internals & Traps) — Freshers to Senior
A senior-level Java Collections interview guide: how HashMap put/get works internally, power-of-two capacity and hash spreading, load factor and resize, treeification, modCount and ConcurrentModificationException, ConcurrentHashMap concurrency, complexity tradeoffs, and predict-the-output traps.