Read a problem, form the approach out loud, then reveal the canonical solution. Pattern-tagged practice for coding interviews.
Each card is a full problem statement with staged hints, a worked solution, and the complexity of the intended approach. Every problem is tagged with the pattern it belongs to, so a session doubles as recognition practice. Cards are drawn with spaced repetition, so the ones you miss come back sooner and the ones you know back off. Progress is kept in your browser.