Built in the margins
Progress Note was built by two residents, one in surgery and one in anesthesiology — between overnight calls and journal clubs — out of frustration with study tools that treat every learner the same.
The idea was simple: the best study session is the one that knows exactly what you're about to forget. Everything in Progress Note — the adaptive engine, the spaced review, the cited explanations — follows from that.
Before it was a product, the idea was put through MIT's startup-validation process and shaped by conversations with learners at every stage of training. The questions are checked against peer-reviewed literature and specialty-society references, so what you study holds up.
It's still built the same way: by people who have sat these exams, for people who are about to.