Did the Splunk onsite about six weeks ago for a senior SWE (L5 equivalent) on a platform team. The whole thing was virtual, four back-to-back 55-minute rounds with a short break in the middle. Here's the breakdown.
Round 1: Coding (with interviewer live) This wasn't a leetcode grind. The problem was more of a "implement a feature in a system you're building" style. I got a prompt involving parsing and aggregating structured data. Medium difficulty, but they expected clean, readable, production-ish code. They asked me to talk through my approach before coding and checked in twice during. Very collaborative, almost like pairing.
Round 2: System Design Log/event pipeline design, which I'd prepped specifically. See the other thread I saw on here about this. The key for me: I drove the design proactively and asked clarifying questions upfront instead of waiting for hints. They pushed on consistency tradeoffs and multi-tenant isolation. I felt solid here but the interview ran a few minutes long which I thought was a bad sign. It wasn't.
Round 3: Behavioral with EM Star-method questions. Conflict resolution, technical disagreement, ambiguous project. Pretty warm interviewer. I was tired by this point (third straight 55-minute session) and I think my answers got a bit looser. Recommend front-loading your sharpest stories.
Round 4: Hiring manager conversation This was less structured. More of a "let's see if this makes sense" conversation. They walked through my background, asked what kind of problems I like working on, and talked about what the team is actually building. This is where you ask your own questions. Have real ones.
Timeline from onsite to verbal offer: nine days. Not bad.
Total loop from OA to offer: about 5 weeks.
One thing I'll add: Splunk interviewers in my experience were genuinely interested in how I think, not in catching me out. If you mess up a step and course-correct, they note the correction as a positive signal, not the mistake.