Labs · Interview traps

Watch the bug happen. Then watch the fix.

Backend bugs that show up in senior interviews and in production. Each one is a real recorded run against a real database: step through it, see which line every request is on, and see the exact row that goes wrong.

1. 01The double-booked seatTwo users hit 'Book' on the last seat at the same moment. Your code checks availability first. Who gets the seat?✗ Seat A1 sold 2 times. 2 users were told CONFIRMED.Replay

New traps land with each episode on Instagram and YouTube.