Understanding Java's Virtual Threads: A Game-Changer for Concurrency

Java 21 introduced one of the most significant features in the language's history: virtual threads (Project Loom). If you've ever struggled with the overhead of platform threads in high-concurrency applications, this feature is for you.

The Problem with Platform Threads

Traditionally, each Java thread maps directly to an OS thread. These are expensive:

Each thread consumes around 1MB of stack memory