Java Guru

Learn Java, Spring Boot, Database, System Design, Performance, and Clean Code through concise, easy-to-understand articles grounded in real-world experience.

Featured

• Kafka: Lessons Only Production Can Teach You

  Published: 24 Jan, 2026 |  at  07:31 AM

  No Kafka tutorial prepares you for the 2 AM wake-up call when consumer lag spirals out of control. Hard-earned lessons about Kafka in production.

• High-Load System Design: Comprehensive Solutions from Front-end to Back-end

  Published: 21 Sep, 2025 |  at  04:32 AM

  A comprehensive guide to high-load system design: from frontend optimization, caching, query optimization, backend patterns, request management, to monitoring and autoscaling.

• Saga Pattern: When Theory Meets Reality

  Published: 2 Sep, 2025 |  at  09:02 AM

  Real-world lessons from implementing Saga Pattern: partial failure, imperfect compensation, duplicate events, and the trade-off between Orchestration and Choreography.

• Hundreds of Orders Vanished in Just 3 Minutes – All Because of One Forgotten Config Line

  Published: 18 Jun, 2025 |  at  03:13 PM

  A real case study on the consequences of forgetting graceful shutdown configuration in Spring Boot: lost orders, Kafka messages, and lessons learned.

• I Don't Like Microservices, and Here's Why

  Published: 1 Jun, 2025 |  at  01:52 PM

  A real-world perspective from a backend developer: when to and when not to use microservices, trade-offs with monoliths, and lessons for small teams.

Recent Posts

• How Java Actually Works: Inside the JVM from Bytecode to Garbage Collection

  Published: 10 Aug, 2026 |  at  10:00 AM

  Follow the journey of a Java program from source code into the JVM — method calls, object allocation, JIT optimization, and garbage collection explained at a deeper level than typical stack-vs-heap tutorials.

• Java Threads: From Thread Pools to Virtual Threads

  Published: 9 Aug, 2026 |  at  12:00 AM

  A deep, production-oriented guide to Java concurrency with 31 runnable examples: what threads really are, why shared state breaks, how thread pools and backpressure work, why more threads can be slower, and what Virtual Threads actually change under the hood.

• Why Java?

  Published: 11 Jul, 2026 |  at  10:00 AM

  A comprehensive look at why Java remains one of the most important programming languages for backend systems, enterprise software, and serious software engineering careers.

• Security Considerations When Participating in Software Development Projects

  Published: 9 Nov, 2025 |  at  02:55 AM

  Comprehensive security best practices for developers, DevOps, QA, and project managers: from secure coding and secret management to threat modeling and SDL.