Just wrapped my Genentech onsite last month. Writing this up because I couldn't find a clean recent post and the older stuff is from 2022-2023 when the process was apparently different.
Location: South San Francisco campus. In-person. They booked travel and the hotel themselves, which I appreciated. The campus is huge and kind of beautiful in a "this is a serious company" way.
Format for a Senior SWE role: Hiring Manager intro: 30 min (not evaluative, more like a mutual vibe check) Coding round 1: 45 min, one medium LC problem with a follow-up Coding round 2: 45 min, one design + implement problem (smaller scope than a full system design) Lunch with the team (not evaluative, but be a normal human) System design: 60 min (covered separately in another thread) Behavioral / values: 45 min with a different IC Wrap with recruiter: 15 min
Total time: about 5.5 hours including lunch. Long but it moved fast.
Coding rounds: The problems felt like LeetCode medium. Nothing crazy. One was around graph traversal, the other around interval merging with a twist specific to their domain. The interviewers were collaborative, not poker-faced. If you're close, they'll say something.
The behavioral round: this was with a non-engineering IC, maybe a technical program manager. Questions were genuinely thoughtful. "Tell me about a project where the technical debt built up and what you did about it" and "describe a time you disagreed with a PM's priority and how it resolved."
Debrief timing: I heard back 9 business days later with an offer. Apparently their debrief happens the same day, which is encouraging. The delay was mostly the comp approval process.
Overall: a more human process than most of the big-tech onsites I've done. Recommend.