Java Backend Interview Prep

Interview-focused Java backend revision with a 7-day path: Day 1 Core Java, OOP, exceptions, and memory; Day 2 collections, maps, sorting, trees, stacks, and queues; Day 3 design patterns, SOLID, coupling, and cohesion; Day 4 Spring Core, Spring Boot REST, HTTP codes, JUnit, and Mockito; Day 5 Hibernate ORM, DBMS, ACID, indexing, deadlocks, and concurrency control; Day 6 Java concurrency, security, OAuth, idempotency, distributed transactions, containers, and microservices; Day 7 HR/project prep with modernization, refactoring, monolith-to-microservices, and mentor-style revision.