Notes on how Billy is built and why.
Completion and mastery aren't the same number, and confusing them costs tutors real preparation time. Here's how Billy's dashboard keeps them apart.
Billy doesn't serve exercises from a fixed sequence — each notion has its own engine that picks the next one from real performance.
Billy's AI guide runs under a strict Socratic policy — hints and questions only, never the answer. Here's why that constraint is the whole point.