The Daily Rep.

A rep is one engineering question you answer from memory, in about thirty seconds, followed by an explanation of why the right answer is right. That second part is the point. Retrieval practice, recalling something without looking it up, is what turns recognition into recall. Reading a doc feels like learning; answering a question you cannot look up is learning. One rep a day keeps the fundamentals warm, so the judgment is there when a code review or an incident asks for it.

• Answer today's question. No account needed.
• Pick a path and the questions follow the work you actually do.
• A free account unlocks three reps a day, picked for you, with streaks. Pro adds practice on demand: any topic, any level, no daily cap.
• The same questions power live team challenges and the Slack daily rep.