Java
JavaOOP Interview Questions in Java (With Code & Traps) — Freshers to Senior
A senior-level Java OOP interview guide covering the four pillars with mechanics, runtime vs compile-time polymorphism, method hiding, field shadowing, exact overriding/overloading rules, interfaces vs abstract classes, the diamond problem, SOLID principles with code, and object-model traps.
JavaTop Java Interview Questions & Answers (Freshers to Senior)
A senior-level Java interview guide covering JVM/JRE/JDK internals, memory areas, String immutability and pooling, the equals/hashCode contract, pass-by-value, final/finally/finalize, static init order, autoboxing caches, type erasure, and hard predict-the-output problems.
JavaJava Design Patterns & Best Practices (Beginner Guide)
Write clean, maintainable Java: the design patterns you already use in Spring, the SOLID principles in plain English, practical best practices, and avoiding over-engineering.
JavaDeploying a Spring Boot App to Production (Beginner Guide)
Get your Spring Boot app online: build a production jar, choose a host (PaaS vs VPS vs cloud), set prod config and secrets, add HTTPS and a domain, then monitor it.
JavaDockerizing a Spring Boot App (Beginner Guide)
Learn to containerize Spring Boot with Docker: what containers and images are, writing a Dockerfile, build and run commands, multi-stage builds, and docker-compose.
JavaSpring Boot Async & Scheduling (Beginner Guide)
Do background work in Spring Boot: @Async to run slow tasks off the request thread, and @Scheduled with fixedRate and cron to run jobs automatically on a timer.
JavaSpring Boot Caching for Speed (Beginner Guide)
Speed up Spring Boot apps with caching: how caching works, @EnableCaching, @Cacheable to store results, and @CacheEvict to avoid stale data. Plus when to use Redis.
JavaSpring Boot Actuator & Logging (Beginner Guide)
Monitor and debug production Spring Boot apps: Actuator health and metrics endpoints, proper logging with @Slf4j and log levels, and configuring output per environment.
JavaSpring Boot with PostgreSQL: Connect a Real Database (Beginner Guide)
Connect Spring Boot to PostgreSQL step by step: add the driver, configure the datasource with env-var credentials, create the database, and persist data across restarts.