Your question is Scalable Systems and Databases. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Describe how you would design a scalable software system and choose between SQL and NoSQL databases.
Explain how you would clarify requirements, estimate scale, partition the architecture, and select storage technologies for transactional, analytical, feature, and high-throughput workloads. Include an ML-serving path with appropriate offline and online components, and discuss consistency, availability, latency, cost, observability, migration, and failure recovery. State assumptions explicitly and justify tradeoffs rather than naming a database without workload analysis.