How does Scala support backpressure in reactive streaming systems?

Backpressure ensures consumers control data flow rate to avoid overload in streaming pipelines.

In Scala streaming frameworks like Akka Streams and FS2, backpressure is a core mechanism that allows downstream consumers to signal demand upstream. This prevents buffer overflow and system collapse under high load. The Reactive Streams specification standardizes this behavior across JVM streaming libraries. It ensures systems remain stable even when producers are faster than consumers.