Finished my Genentech loop last month for a Senior SWE role in their Research and Early Development tech group. The system design round was the one I was most curious about because Genentech is not a typical big-tech product company. Here's the honest rundown.
The prompt was genuinely domain-adjacent. They gave me a scenario around designing a data ingestion pipeline for clinical trial results, not "design Twitter" or "design a URL shortener." So if you're coming from a pure product-company background, spend 30 minutes thinking about how pharma data actually flows before your interview. Patient data, consent workflows, batch processing at weird cadences. That context mattered.
Format: 60 minutes, one interviewer (a Staff IC from the platform team). No live coding, whiteboard / Google Jamboard. They wanted: requirements gathering, rough capacity estimates, component breakdown, then a deep dive into the part you're most confident in.
What they probed: API contract between services, how you'd handle schema evolution (huge in biopharma), idempotency on retries, and briefly, access control / audit logging. The audit logging question felt almost behavioral: "walk me through what happens when a researcher tries to pull data they shouldn't have access to."
I'd call the difficulty roughly what you'd see at a mid-tier tech company, not Google/Meta bar. But the domain specificity makes it feel harder if you haven't thought about it. They're not trying to trick you. The interviewer was collaborative, nudged me when I went too deep on the wrong thing.
One thing that hurt me: I spent too long on the database schema and not enough on failure modes. When they asked "what happens if the ETL job crashes halfway through?" I was a bit flat. That round felt like a 3.5/5 from my side. Still got the offer, so it wasn't fatal, but I'd prep failure modes and recovery explicitly.
SF Bay Area, 2026. Happy to answer questions on the other rounds too.