Did CrowdStrike's virtual onsite last quarter for a senior SWE role on their threat intelligence platform team. It's technically virtual but they call it an onsite internally. Here's the actual breakdown.
Format: four sessions over one day, back to back with 5-min breaks. Total block was 4.5 hours on my calendar.
Session 1 - Coding (60 min). Two problems. First was medium-tier, graph BFS variant. Second was a medium-hard simulation. Both in CoderPad. Had to run code against test cases they provided. The second problem has a trick: read the problem statement twice. Mine had a constraint buried in the second paragraph that changed the time complexity target.
Session 2 - System design (60 min). Domain-specific prompt (threat detection pipeline, real-time event processing). This went long. We spent the last 15 minutes on reliability and failure modes. Know how your design degrades gracefully under load.
Session 3 - Behavioral (45 min). With a senior engineer, not a people-ops person. That matters. They're probing your actual experience, not checking boxes. See the other thread on values for the question patterns.
Session 4 - Cross-functional / culture (30 min). Eng manager from a separate org. Very conversational. They wanted to understand how I collaborate cross-functionally. I asked about team structure and how decisions get made. That worked well.
Debrief timeline: 7 business days. Recruiter called with verbal offer, then formal offer packet came 2 days later. Total loop including debrief: about 40 days.
Things that I've heard tank people at the onsite: Failing to ask clarifying questions at the start of system design. Jumping in without scoping the problem reads as weak. Not having metrics in behavioral answers. "We improved performance" is incomplete. "We reduced detection latency from 4 seconds to 800ms" is what they want. Talking too fast in the behavioral round when nervous. They will interrupt to dig deeper so leave room.
Overall: rigorous but fair. The problems felt like they were actually connected to the work.