A live marble diagram for Spring WebFlux / Project Reactor. A Flux emits values over time; toggle operators and press play to watch map, filter, take, and delay transform the stream marble by marble.
map doubles each, filter keeps evens, and take(3) completes the stream early (the green bar) after 3 pass, so later values never even run. Turn filter off and watch more marbles flow. Add delayElements and the whole output lane shifts right. Flip to Mono and the source emits at most one value then completes. Operators are lazy: nothing runs until you subscribe (press play) — that's the reactive model.