Just finished the Dell senior SWE loop in February so this is fresh. The system design round is 60 minutes with one or two interviewers, usually both from the team you're interviewing for rather than a separate panel. No dedicated system design specialist like you'd see at Google.
The prompt they gave me was classic distributed-system territory: design a notification service that handles millions of events per day across multiple regions. Pretty standard for an L5 / Senior IC interview but the depth they wanted was interesting.
What they actually cared about: Failure modes. They pushed hard on "what happens if this queue fills up" and "how does the consumer recover." Have a real answer, not just "add more workers." Trade-offs between consistency and availability. They didn't want the CAP theorem lecture, they wanted you to say which one you'd pick and why for this specific use case. Rough capacity math. Not precise, but being able to say "okay at 1M events/day that's about 12 events/second at steady state, so a single queue is fine, here's where you'd shard" goes a long way. They asked zero questions about fancy infrastructure (Kafka, Flink, Kinesis). Whiteboard it with boxes and arrows and explain your reasoning.
What did NOT come up: deep Kubernetes orchestration, anything cloud-provider-specific, ML serving infrastructure. Dell runs a lot of on-prem and hybrid stuff so the questions felt more datacenter-grounded than pure cloud.
One thing that surprised me coming from big tech: they gave much more time for you to think out loud. At FAANG the system design rounds move fast. Here the interviewers let you explore. Use that space, but don't ramble without direction.
Leveling felt roughly equivalent to what big tech would call L5 or IC4. Expectation is you can scope a project, identify risks, lead junior engineers through the build.
I passed and got an offer. The interview itself was solid, not grueling. If you're worried about system design: practice the "go wide then go deep" structure and have failure-handling answers ready for every component you draw.