Real-time help for system design interviews
System design is the interview with no right answer and every way to go wrong: forty-five minutes, a whiteboard, and a prompt like “design a chat app” that could fill a book. Candidates rarely fail it for not knowing the pieces — they fail it for skipping requirements, diving into one component and running out of clock, or freezing when the interviewer pushes on a trade-off. PiriPiri AI listens to the whole conversation live and keeps the shape of a strong answer in front of you while you do the designing.
Hold the structure interviewers grade against
Every system design rubric rewards the same arc: clarify functional and non-functional requirements, estimate the scale, sketch the core design, then go deep where it strains. Under pressure it is astonishingly easy to skip step one. As the prompt lands, PiriPiri AI lays that arc out with the specifics of the question folded in — the clarifying questions worth asking, the axes the design will be judged on — so you spend the first five minutes the way strong candidates do.
The numbers you blank on, on demand
Back-of-envelope estimation is where minds go empty: requests per second from daily actives, storage growth per year, whether the working set fits in memory. Ask by voice or hotkey and the arithmetic and the standard reference numbers arrive as short bullets you can fold into your own reasoning — instead of stalling the call while you rebuild them from scratch.
Trade-offs, when the follow-up comes
The real test starts when the interviewer pushes: why this database, what breaks at ten times the load, how do you handle the celebrity user? When a follow-up lands, the overlay drafts the considerations — consistency versus availability, fan-out on write versus read, where the cache actually helps — while you keep talking, so the pause where you would have scrambled becomes a beat to choose your position.
Invisible while you drive the whiteboard
Design rounds mean sharing your screen for the diagram. The overlay is excluded from screen capture, so you can share your entire desktop in Zoom, Google Meet, or Teams and the interviewer sees the whiteboard, not the assistant. You are responsible for following any rules and consent laws that apply to your interview.
Common questions
Does it draw the diagram for me?
No — you drive the whiteboard. It works in words: structure, estimates, trade-offs, and what you have not covered yet, in short bullets beside your call.
Does it know the standard designs?
The classics — URL shorteners, feeds, chat, rate limiters — and the components behind them. More usefully, it hears your interviewer’s specific twist and adapts the structure to it instead of reciting a memorised template.
What if I disagree with a suggestion?
Say so — in the interview. The suggestions are inputs to your design, not a script; interviewers reward a defended choice over a recited one, and the defence has to be yours.
Start with 3 free sessions — no credit card. Also useful for coding and technical rounds and behavioral interviews.