System design interviews, the way they actually happen.
Watch a staff-level candidate and an interviewer go the full 45 minutes. The video stops where the interviewer pushes. You answer first. Then you get on the call yourself.
Free: one full interview and the first two modules. No card.
▶ Design ChatGPT · Staff · 24 min
One loop, every problem
Watch the real thing
Two people, one whiteboard, 45 minutes. The clarifying questions, the first idea that doesn't hold, the time checks. Not a lecture.
Your turn
The video stops where the interviewer probes. Commit to an answer, then see what the candidate said and what mid, senior and staff reach.
Be the candidate
The same interviewer runs the same problem with you, on the same board, and tells you where your answer lands.
Know what's left
Progress by pattern, not by page: leases, fencing, backpressure. The plan fits the date of your interview.
The interviewer steps out and tells you the level.
What junior and mid answers stop at, what senior adds, what made this one staff. Including the parts the candidate got wrong.
| Topic | Junior / mid | Senior | Staff |
|---|---|---|---|
| Reliability | A worker picks up the job | Retries and duplicates | Fences the stale worker everywhere it can still write |
| Peaks | Add more servers | Rate limits | Decides who waits; sheds new work early |
Pricing
Placeholder numbers. One payment, no auto-renew.
Two new interviews a week.
One email when an episode is out. Nothing else.