Module Introduction

1. What This Module Covers

A whiteboard design is a claim. Production is where the claim gets tested.

Interviewers close that gap with a family of questions that begin where your diagram ends.

• "How does a request find a healthy instance?"
• "How do you debug a slow request across nine services?"
• "How do you deploy a change without an outage?"
• "How does service B know the call really came from service A?"

These are operations questions. **At mid and senior levels they count for a lot, because running the services is where the real cost of microservices lives