Provide interviewer with general idea on how you perform your tests. For load test, it can be generating hundred users access a web page at the same time. For stress (endurance) test, it can be stressing the server for extended hours.
What would you want to become in 5 years time? Ans: I said Senior consultant or product consultant handling a key portfolio. Interview said, we are just looking for senior developer, we do not have scope for you.
First, look at what missing information you still need to know and ask about it. Then take some time to think about a good initial solution, but be open to new requirements developing, as well as taking in feedback from your interviewers. It's good to approach this as a team discussion that would happen during the course of working together.