Streaming and Backpressure

When data is too large to hold in memory or keeps arriving without end, you handle it as a stream, one piece at a time, with bounded memory, rather than pulling it all in. Backpressure is the mechanism that keeps a fast producer from swamping a slow consumer, by signaling 'slow down' instead of buffering without limit until memory runs out. Applied-AI interviews test it because AI pipelines chew through huge datasets and token streams, and the naive load-everything approach OOMs while unbounded buffering crashes under load.