Bulb Principal Engineer interview questions

After phone screen with recruiter that sounded very excited, since I was already a Principal Engineer, received a take home test. Had to write it in TypeScript, although I specifically said I don't have previous experience with it. In the end, spent 8 hours across the weekend to complete it. The test itself didn't seem very complicated, but was long, around 1K LoC including tests. Reject straight after, saying I didn't implement some secret requirements.