Cesium is an end-to-end machine learning platform for time-series, that computes machine learning features, builds models, and does prediction. Cesium has two main components—a Python library, and a web application platform that allows interactive exploration of machine learning pipelines. The Cesium library is specifically designed to handle irregularly sampled time series, as is common in astronomy. BIDS Faculty Affiliate Joshua Bloom and BIDS Senior Research Data Scientist Stéfan van der Walt contribute to this platform.