Your question is API Scalability, Security, and Design. 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).
For an API you built, how will you ensure scalability, security and best practices, and how would you design the schema of the API? Asked in the L1 stage. Focus on how you would structure the API, protect it, and keep it reliable as traffic grows.