Module Introduction

1. What This Module Covers

Your design has two services and an arrow between them. One question now exists, whether or not the interviewer says it out loud. What happens when the service on the right does not answer?

Ask that question yourself, before the interviewer does. It is the single strongest signal in microservices interviews. This module gives you a method for answering it.

Failure is not an edge case you handle at the end. At scale, rare means constantly. A call that fails once in a thousand times fails ten thousand times a day at ten million calls.