Java Application Performance: Optimization and Profiling

The book "Java Performance" is a practical guide for developers who want to learn how to identify and eliminate bottlenecks in their Java programs. The author thoroughly examines the internal structure of the Java Virtual Machine (JVM), garbage collection mechanisms, memory and multithreading management, as well as modern profiling tools.

The book consists of three parts:

• Performance Fundamentals — understanding the JIT compiler, bytecode, and JVM tuning.
• Profiling and Monitoring — using VisualVM, JProfiler, Java Flight Recorder, and other tools to analyze CPU, memory, and threads.
• Practical Optimization — algorithm optimization, working with collections, reducing GC overhead, asynchronous programming, and benchmarking with JMH.

Who this book is for:

• Junior+ and Mid-level Java developers looking to advance to the next level.
• Team Leads and architects responsible for application performance.
• Professionals preparing for technical interviews (JVM and GC topics are frequently covered in interviews).

What you will learn:

• How garbage collectors (G1, ZGC, Shenandoah) work and when to choose which one.
• How to properly configure JVM parameters (-Xms, -Xmx, -XX:NewRatio, etc.).
• How to find memory leaks and thread issues.
• How to write benchmarks without making common mistakes (JVM warmup, dead code elimination).
• How multithreading affects performance and how to avoid contention.

The book is written in a lively style with numerous code examples and real-world cases. It is suitable both for self-study and as a reference for solving specific performance problems.

Recommended for readers already familiar with the basics of Java who want to gain a deeper understanding of how to make code run faster.