Welcome to your interview.
The question is on your right: RxJS and Observables for Async. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
What is the purpose of RxJS and how do you use Observables to handle asynchronous data?