Deciding Before the Future Arrives: Online and Streaming Algorithms, from Ski Rental to the Secretary Problem

Deep End Era. Engineering with Sankalp · Oct 28, 2026 · 53m

A fictional cloud platform lead must decide, every week, whether to keep paying by the hour for servers or commit to a year-long reservation, without knowing whether the traffic spike will last. A fictional content-delivery engineer must choose which video to throw out of a full cache each time a new one is requested. Neither can see the future, and both are judged against someone who can. From a 1949 lecture on choosing a fiancée and Kepler's eleven marriage candidates to a 1969 paper showing that more memory can make a computer slower, this is the theory of acting well when you can't know…