Finished a 5-round virtual onsite for a senior ML role on the Autopilot AI team. Here's the honest breakdown.
Format: 5 rounds back-to-back over one day (with one 30-minute break in the middle). Fully virtual, Zoom. Each round was exactly 60 minutes.
My five rounds: Coding (algorithms, 1 problem) Coding (domain-specific, involved matrix operations) ML system design (designing a perception pipeline component) Behavioral Hiring manager conversation (more strategic, less testing)
Other roles might have different mixes. A product SWE friend who did their onsite around the same time had 2 coding, 1 system design, 1 behavioral, 1 HM. No second domain-specific coding. So the exact mix depends on the team.
Pacing: The day is long. By round 4 I was tired. This matters. Bring water. Take the break seriously. I ate something actual during my 30 minutes and it helped.
Interviewers: All were engineers or engineering leads on the actual team, not HR or generalist interviewers. One of my coding interviewers had been at Tesla for 4 years on Autopilot software. That means the questions are relevant to real problems, but it also means they have opinions. When I proposed a solution, they pushed back with "we actually tried that approach and hit X problem." That's both challenging and kind of great because you get real signal on how they think.
What matters most: In my experience the behavioral and HM rounds carry a lot of weight in the final debrief, not just the coding scores. Tesla seems to weight culture and drive pretty heavily. A friend who aced the coding rounds but seemed passive in the behavioral didn't get an offer. Someone I know who flubbed one coding problem but was sharp and direct in behavioral and HM did get through.
Timeline after onsite: They told me 5-7 business days. Actual response came in 9 business days. One extension email in between. Don't read too much into the delay.