Your question is Temperature Data Store. 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).
Design a data structure to store temperature data per city and date with two APIs: save data from IoT device streams, and find the average temperature of a city
Asked in the Round 1 stage. Reported follow-up: optimize the average query. Explain your data structure, API behavior, time and space complexity, and how you would handle repeated dates, missing data, and concurrent writes.