Advanced Questions

Definition

Deep-dive questions assessing knowledge of Multi-Stage Builds, Security Hardening, Orchestration, and CI/CD pipelines.

Explain Like I'm New

Proving you know how to safely put Docker on the public internet without getting the company hacked or crashing the server.

Real World Example

Question: 'Walk me through how to reduce a 1GB Golang Docker Image down to 15MB, and explain why that is critical for security.'

Common Use Cases

•DevOps Engineer Interviews
•SRE roles

Interview Questions

basic

Why should you never run a container as the 'root' user in production?

intermediate

How does Layer Caching work, and how should it dictate the order of commands in your Dockerfile?

Flash Cards

Question

Why not root?

Click to reveal answer

Answer

Because if an attacker exploits a vulnerability in your application and achieves a 'Container Escape', running as root means they instantly gain Superuser control over the entire physical Host server.

Question

How does Layer Caching work?

Click to reveal answer

Answer

Docker caches each command line as an image layer. If a line changes, that layer and EVERY layer below it is invalidated and must be rebuilt. Therefore, commands that change rarely (like installing OS dependencies) must go at the top, and commands that change constantly (like copying source code) must go at the absolute bottom.