Learn from short, focused guides you'll actually finish. Then practice explaining your design out loud to an AI interviewer that asks real follow-up questions.
Free interviews. No daily limit.
Reading builds recognition. Interviews test recall. That's why practice has to include speaking.
First principles, worked examples and the reasoning behind each decision, without the padding.
A product-details endpoint reads the same popular records thousands of times. Each request loads product metadata, current price, inventory, and image references from the database. The database is healthy, but repeated work pushes its latency upward, and the endpoint slows down with it.
Speak or type your answer. The interviewer asks follow-ups, like a real one would.
Try an AI interviewShort recall prompts bring back the key ideas, so they're there when you need them.
Revisit a conceptAfter each interview you get a breakdown by stage, the moments that needed more depth, and the guides to read next.
Get your own reportEach guide gets to the point: the idea, the trade-offs, a worked example. No filler.
It plays the interviewer, gives feedback on your answer, and quizzes you on recall.
Short recall prompts bring back the key ideas, so they're there when you need them.