Retell AI Software Engineer Interview Experience — Phone Screen, Four Onsite Rounds, and a Founder Who Muted Himself

Their HR seems to be outsourced to some third party — they were actually pretty enthusiastic though.

Phone screen: coding.

Onsite: four rounds.

Round 1 was practical coding, I don't even remember what exactly it was anymore. They allowed using AI for code gen.

Round 2 was also practical coding, the problem was pretty long and I don't remember the details either. All I remember is that you had to carefully read their API docs. Honestly I really couldn't be bothered to read docs during an interview, I'd spent all my prep time on algorithm questions instead. But I get it — they clearly want to hire people who can be put to work like oxen and horses right off the bat (HR straight up told me 70 working hours a week is expected — !! And it's 5 days RTO, remote on Saturdays, with only Sunday actually off, lol).

Round 3 was system design, Google Docs. The main focus was handling parallel editing. The correct answer is supposed to be either CRDT/OT or a global sequence number. It's actually a pretty basic topic, but since this was the first system design round I'd ever done, I didn't have a deep enough grasp of the Google Docs problem at the time, so I only brought up the global sequence approach and never got to CRDT/OT.

Round 4 was the HR round, just a short chat. The main thing they asked was whether I could accept working 70 hours a week, lol.

Anyway this one was just for practice early on, so I didn't put any real effort into prepping for it. The interview style wasn't really my thing either. Overall it's a fast-growing company (hiring like crazy), but it gives off a bit of a fly-by-night vibe. Also, the package they mentioned up front is nowhere near enough to justify 70 hours a week. I'd say it's only really suited for young people who have life to spare and aren't afraid of dying. Anyone else who took the job would probably actually work themselves to death, lol.

Addendum (2025-11-30): One more thing — the guy on the phone screen was pretty nice, seemed like a TL who'd joined not too long ago. In onsite round 2, the API-call one, the interviewer was one of the founders. Right off the bat he said he expected me to figure everything out on my own the whole time per the requirements, then he just muted himself and went off to do his own thing for the rest of it.