Performance — performance optimization, benchmarking, and profiling in Java applications
A beginner-first JMH tutorial, verified on JDK 25 and JMH 1.37: dead-code elimination, Blackhole, constant folding, warmup, forks, state scopes, -prof gc and percentiles, each shown with real captured output.
A complete migration guide covering every scenario: java.util.Date, Calendar, java.sql types, SimpleDateFormat, Jackson serialisation, Hibernate/JPA mapping, Spring MVC binding, and five migration pitfalls — with before/after code examples for Java 8 through Java 21.
20 copy-paste AI prompts for Java concurrency and CompletableFuture — from basics to advanced production patterns and debugging. Covers thread pools, ExecutorService, CompletableFuture chaining, fan-out/fan-in, timeout handling, virtual threads, deadlock diagnosis, thread dump analysis, and full concurrency audits.
A hands-on comparison of serverless Java AI inference on AWS Lambda, Azure Functions, and Google Cloud Run — with real benchmark data, cost tables, a clear winner recommendation, and code you can run.
Project Leyden brings AOT compilation and persistent caching to standard JVM Java — no native binary required. Learn how it works internally, where it wins, where it fails, and how to use it correctly in production.
Three identical Spring Boot 4.1.1 endpoints — I/O-bound and CPU-bound — re-benchmarked on JDK 25 under platform threads, virtual threads, and WebFlux. Real numbers, a benchmark-methodology bug caught and fixed along the way, an event-loop-starvation failure mode isolated CPU benchmarks miss, and a decision framework: if your service does X, pick Y, because Z.
A JEP-by-JEP deep dive into Java 25 LTS — the features that will actually change how you write and profile Java. Each section includes a before/after code example, an explanation of what the JVM does differently, the pitfall to avoid, and a copy-paste AI prompt to retrofit your existing codebase. Covers JEP 495, 494, 485, 492, 488, 491, 454, and JFR method profiling.
10 copy-paste AI prompts for Java performance optimization. Covers GC log analysis, memory leak detection, virtual thread evaluation, thread dump contention analysis, HikariCP tuning, Stream pipeline optimization, JVM flag review, JMH benchmarking, hot method profiling, and full production performance audits.
10 copy-paste AI prompts for reviewing and improving Java code quality. Covers SOLID violations, thread-safety bugs, virtual thread carrier pinning, N+1 query patterns, resource leaks, exception handling, null safety, logging quality, and full quality audits. Works in Claude, ChatGPT, Gemini, and Cursor.
Records, pattern-matching switch, virtual threads, sequenced collections, scoped values and structured concurrency from Java 21 to Java 25 LTS, each compiled and run on JDK 21, 25, 26 and 27: what is really final, when virtual threads stopped pinning, and what 26 and 27 mean for the road to Java 29.