did the system design round for a senior SWE (what i'd call roughly L5 equivalent) role at abbvie commercial IT last quarter. posting because the framing is a bit different from what you'd expect if you've only done FAANG-style system design.
the problem they gave me: design a patient data notification system. sends alerts to care coordinators when a patient hasn't refilled a specialty medication. sounds niche but it decomposes into pretty standard pieces: event ingestion, scheduling, notification dispatch, observability.
what they focused on: data consistency. they asked what happens if a notification fires twice. idempotency came up pretty quick. HIPAA compliance implications on data storage and transit. you don't need to be a compliance lawyer but knowing that PHI has specific requirements (encryption at rest, audit logging, access controls) is table stakes here. failure modes. what if the downstream SMS gateway is down? dead letter queues, retry with backoff, all of that. how you'd test it. they wanted to hear about integration testing and how you'd validate in a staging environment before touching real patient data.
what they didn't do: whiteboard the database schema in detail, ask about specific AWS services by name, or push on scalability to google-scale numbers. the scale is more like millions-not-billions, which is actually a more realistic and in some ways harder design constraint.
interviewer was a principal engineer who asked good follow-up questions. he wasn't looking for a perfect answer, he was looking for structured thinking and intellectual honesty about tradeoffs.
one thing i'd add: they care about how you communicate. abbvie has a lot of cross-functional teams (medical, regulatory, commercial) and engineers have to translate technical decisions for non-technical stakeholders. i mentioned that a couple times and it landed well.
total duration: 60 minutes. felt a little rushed at the end.