Voice + whiteboard · staff-level feedback

The mock interview that actually talks back.

Sit across from a senior AI interviewer. It speaks, listens, and watches your whiteboard in real time — probing your design just like a staff engineer would — then hands you an honest scorecard.

One free session · no card required · backend & iOS tracks today.

Design a URL shortener · Phase 3 / 6 · High-level design
Client
API Gateway
App Service
Cache
Postgres
Transcript
Interviewer
What happens to that database at peak traffic?
You
I'd add a read replica and cache hot keys…
Interviewer
Good — so how do you keep the cache from going stale?
Speaking…

Built for engineers with a real interview on the calendar

Felt like the real thing — it caught me hand-waving over replication and wouldn't let it go.
Backend engineer, prepping for a senior loop
The scorecard was more useful than three peer mocks. Specific, honest, actionable.
iOS engineer
Talking out loud with something that sees my diagram fixed my pacing before the real interview.
Full-stack engineer
How it works

From cold start to honest feedback in one sitting

No setup, no scheduling, no awkward peer matching. Open a problem and start talking.

01

Pick a problem

Choose a preset system-design prompt for your track — backend or iOS — or bring your own.

02

Talk & sketch

The interviewer greets you out loud and runs a phased 45-minute session while you think aloud and draw on the whiteboard.

03

Get a scorecard

End the session and receive a staff-level rubric: what you nailed, what to fix, and a model answer for your deep-dive.

Two ways to practice

Get grilled, or get taught

Same voice, same whiteboard — you choose whether the AI assesses you or coaches you.

🎤 Interview me

A rigorous mock

A skeptical staff engineer probes your design, pushes back on weak spots, and never hands you the answer. Ends with a judgmental scorecard so you know exactly where you stand.

  • Phased like a real 45-minute loop
  • Surfaces flaws with questions, not lectures
  • Hire / no-hire scorecard with scores
🧑‍🏫 Learn with me

A guided lesson

A patient mentor teaches as you go — answering your questions, explaining tradeoffs, and building your intuition until the design is complete. Ends with an encouraging recap, not a verdict.

  • Ask anything, any time
  • Teaches the principle behind each decision
  • Recap of concepts + what to study next
Why it works

Closer to the real interview than a peer mock

It sees your whiteboard

The interviewer reads your actual diagram every turn — you only get credit for what you draw, just like the real thing.

Phased like a real loop

Clarify, estimate, high-level design, deep-dive, scale & failure, wrap — it moves you through the arc a real interviewer follows.

Voice-native

You talk, it talks. No typing. That's the skill a system-design interview actually tests — thinking clearly out loud under questioning.

An honest scorecard

Every point is tied to something you said or drew, with a model answer for the component you went deepest on.

Learn mode too

Not interview-ready yet? Switch to a coaching session that teaches you the material instead of grading it.

Bring your own problem

Practicing for a specific company or domain? Paste your own prompt and the interviewer adapts to your track.

The payoff

A scorecard you'd actually act on

Not vibes — a specific, staff-level read on how you did, tied to exactly what you said and drew.

Overall: Lean HireDesign a URL shortener
Requirement clarification
High-level design
Deep-dive depth
Scale & failure handling
Communication
What to work on: You didn't address what happens when the primary database fails at peak — no replication or failover story. That's the gap between lean-hire and a clear hire here.
Pricing

Cheaper than one coffee per session

A live human mock runs $100 or more. Whitepad gives you unlimited access to a tireless senior interviewer for a fraction of that.

Start with one free mock — no card required.

FAQ

Questions, answered

What kinds of interviews does it cover?+

System-design interviews for backend and iOS engineers today, with more tracks coming. You can also paste your own problem for a specific company or domain.

Do I need a microphone?+

Yes — it's a spoken interview, just like the real thing. Use headphones so your mic doesn't pick up the interviewer's voice.

How long is a session?+

About 45 minutes, phased like a real onsite. You can end early and still get a scorecard for what you covered.

Is it actually good feedback?+

The scorecard is generated by a top-tier model reasoning over your full transcript and final whiteboard, with every point tied to something concrete you said or drew.

Can I cancel anytime?+

Yes. Plans are month-to-month (or annual for a discount), and you can cancel from your account in one click.

Your interview is coming. Practice out loud.

Take your first mock free. Talk through a real problem, get a staff-level read, and walk in ready.

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