mycodedojo · est. 2020
Field notes from the code dojo.
Homelab, self-hosting, AI agents and full-stack craft. I'm Michael Cooper, a senior full-stack engineer who runs most of his stack on hardware in his own house. These are the notes I write while I train.
Featured note
Zod: Stop Trusting Your API Responses at Runtime
TypeScript types vanish at runtime. Zod gives you a single source of truth for shape validation *and* your TS types — here is how I use it in real projects.
Fresh off the mat
Latest notes
TIL: Object.groupBy() — JavaScript Finally Has a Native Group By
ES2024 ships Object.groupBy() and Map.groupBy() — no more reduce() gymnastics just to bucket an array into groups.
Yellow belt
Docker Multi-Stage Builds: Smaller Images, Faster Deploys
Multi-stage builds let you compile and test inside a fat builder image, then ship only the final artifact in a tiny runtime image — the same Dockerfile, no extra scripts.
Brown belt
useCallback and useMemo: When They Actually Help
Most React devs either ignore these hooks or wrap everything in them "just to be safe." Both are wrong. Here is exactly when each one earns its place.
Brown belt
TanStack Query v5: Stop Managing Server State by Hand
If you are still fetching data with useEffect and useState, TanStack Query will feel like a superpower — caching, deduplication, background refetching, and mutations, all handled for you.
Green belt
Running Home Assistant in Docker: From Zero to Your First Automation
How I run Home Assistant in a single Docker container, keep the config in Git, and build automations that actually make life easier.
Green belt
Mastering Modern JavaScript: Patterns You Actually Use
A practical tour of the modern JS features that come up every day — scoping, destructuring, array methods, async/await, and optional chaining.
Yellow belt