Java 21 marks a pivotal moment in JVM history — the arrival of Virtual Threads, a game-changing feature from Project Loom.
For decades, Java’s concurrency model has relied on OS-level threads, each carrying significant memory and context-switch overhead. That model struggled under modern workloads — think thousands of concurrent web requests, reactive microservices, and async I/O.
With Virtual Threads, Java finally delivers structured concurrency and massive scalability without abandoning its core threading APIs.
In this post, you’ll learn:
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How Virtual Threads work internally
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How to migrate from traditional threads
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Real-world code comparisons and performance benchmarks
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Best practices for production-ready adoption