Your question is Kafka Cluster Provisioning. 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).
Kafka: what are topics and partitions, and how do you decide how much to provision for a Kafka cluster?
Explain how topics provide logical streams while partitions provide ordered, parallel, replicated logs. Describe a practical sizing approach covering producer throughput, consumer parallelism, message size, retention, replication factor, broker disk and network limits, recovery capacity, and operational headroom. Include the trade-offs of adding partitions, including ordering constraints and the fact that partition counts are difficult to reduce.