Your question is Owning a Customer-Facing Technical Demo. 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).
Tell me about a time you had to present a live demonstration of an application or proof of concept you built, explain the architectural choices you made, and walk others through how you instrumented it for monitoring and troubleshooting. What was at stake, how did you prepare, and what was the outcome?