How to use it
Pick a deck and an answer time, then flip the card. The question shows and the countdown starts. Answer it out loud, as you would in the room, and stop when the clock runs out. Then go to the next card. The cards come up in a new random order each time through the deck.
- Thinking time gives you a few seconds to gather your thoughts before the answer clock starts.
- +1 minute (or M) adds time if you’re mid-answer.
- Your own decks: press + New deck and type one question per line, or copy a built-in deck and edit it.
- Copy share link puts the whole deck in the link, so a friend or study partner can add it with one click.
There are no model answers on purpose. Saying it in your own words, with your own examples, is the part that needs practice. If you can, record yourself or ask a friend to listen and ask a follow-up question.
The built-in decks
- Behavioral (2 minutes each): stories about your work. Use one real example per answer.
- System design (15 minutes): design a system out loud, from questions about the requirements to trade-offs. Includes designing a RAG system over 10,000 documents and a pipeline that extracts fields from PDFs into a warehouse.
- SQL (3 minutes): queries and concepts to talk or write through. The SQL course lets you run them.
- AI engineering (3 minutes): LLMs, retrieval, agents and evaluation. The LLM, RAG and agents courses cover the background.
Questions
Is anything I type sent anywhere? No. Your decks are saved in this browser only. A share link carries the deck in the part of the address after #, which browsers don’t send to the server; anyone with the link can read it, so keep private notes out of shared decks.
Can I use it on my phone? Yes. Tap the card to flip it; the timer keeps time correctly even if the screen sleeps.
Is it free? Yes, with no account.