Did the full Palantir loop for a senior SWE role earlier this year, NYC-based. The system design round is... not what you'd prep for at a typical FAANG shop. Let me be specific.
They don't give you a classic "design Twitter" or "design YouTube" prompt. The problems are closer to operational systems. Think: how do you build a data ingestion pipeline that handles heterogeneous government data sources, reconciles schema conflicts in near-real-time, and still lets analysts run ad hoc queries without waiting 20 minutes. Or: design a workflow engine that lets non-engineers define multi-step data transformation jobs.
What they're actually evaluating: Whether you understand the trade-offs between batch vs. streaming ingestion How you handle schema evolution and data quality at the input layer Whether you think about the user of the system (often an analyst or operator, not another engineer)
The interviewer was senior, clearly technical, and pushed hard on every assumption. Not in a mean way, more like they expected you to have already thought three steps ahead. When I said "I'd use Kafka for the streaming layer," they immediately asked why not Kinesis, why not Pulsar, and what the failure modes look like when a consumer falls behind.
Depth over breadth. That's the only mental model that matters here. A broad 20-component diagram impresses nobody. Pick the two or three genuinely hard sub-problems and go deep.
Time was 45 minutes. I spent maybe 10 clarifying requirements, 25 designing, 10 getting grilled on specifics. No whiteboard -- all verbal with occasional Excalidraw.
For level calibration: they were targeting L3 equivalent (their leveling is a bit opaque from the outside), which in market terms is roughly senior SWE. The design expectations matched what I'd call a strong senior IC bar, not staff. If you're interviewing for a "senior" title, know your distributed systems basics cold and actually have opinions about them.
Happy to answer specifics if anyone's prepping.