Interview questions
+1. JVM memory areas. Thread safe memory areas, Garbage collector working principle, Java reference types +2. SOLID +3. Collection API: How does HashMap work under the hood, hash collision, Concurrent HashMap +4. Equals and HashCode contract 5. Thread, Volatile vs Synchronized, atomic variables(CAS-compare and swap). How to prevent deadlock. Deadlock vs livelock. Reentrant lock. 6. Error vs Exception 7. Immutable class(how to make object properties immutable, immutable collections) 8. DB index type(clustered, non clustered, composite) 9. DB normalization and denormalization 10. RDBMS vs non RDBMS 11. ACID vs BASE 12. Hash eviction policy(TTL, LRU, FIFO, LFU, MRU, random replacement, ARC). Problem: we have 2GB memory, how to store 15GB data in this cache 13. entity lifecycle 14. dirty check, flush 15. cascade types 16. n+1 problem (entity graph, join fetch) 17. lazy initialization exception 18. idempotency, safe in rest methods 19. IOC, DI, Proxy 20. AOP(cross cutting concerns) 21. comm...