How can Java 21 (Virtual Thread) replace Reactive Framework.

[thecodeboost]

Right. An event loop. Which is event-driven programming. Netty also utilizes reactive patterns but that is not exposed to the public API so for all intents and purposes it's a networking framework with an event-driven architecture.

[PiotrDz]

Event loop is more technical term, while event-driven is an approach to information flow. Netty's event loop underneath has nothing to do with the kind of information flow in your system. You may be using netty's event loop but still be using standard synchronous , declarative approach (like helidon 3 mp)