Programming · by Ren Suzuki · 2026-10-10

Java 25 and Virtual Threads in production: what surprised you most?

Java has evolved at lightning speed recently. With Virtual Threads (Project Loom) structured concurrency, and pattern matching fully matured, the language feels completely transformed from the Java 8/11 days. For folks running modern JVM workloads in production, what was the biggest pleasant surprise, and what caught you off guard?

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Nicolás Díaz · 0 likes

The simplicity of writing synchronous readable blocking code while getting asynchronous high-throughput I/O under the hood is pure bliss. No more ReactiveStreams spaghetti or Mono/Flux callback chains

Minji Kim · 0 likes

Watch out for thread pinning if you have legacy libraries doing `synchronized` blocks around socket I/O. Replacing them with `ReentrantLock` fixed it for us instantly

Minh Nguyen · 0 likes

Pairing Java 25 with Spring Boot 3+ on containerized microservices dropped our memory footprint by nearly 40% compared to our old architecture