Advanced Java Backend Engineering

Advanced topics — implementing from scratch what most developers only use from libraries.

✅ Completed

• Custom HashMap — bucket array, separate chaining, O(1) average complexity

🔨 In Progress

• Custom Thread Pool — ExecutorService-like functionality

📋 Planned

• Reflection API & Custom Annotations
• Java NIO (Non-blocking I/O)
• Spring Boot internals
• Microservices (Kafka, Circuit Breaker)
• System Design (URL Shortener, Chat App)