Week 4 — Platform, craft & capstone

Judge when to use Redis, files, RabbitMQ, Docker, and WebSockets; then test, optimize, challenge, review, and finish Notes P4 as this week’s mini-project.

1. Caching with Redis
No install is required this week. The goal is judgment: when caching solves a real, measured problem, and when it just adds a second source of truth to babysit.
Open
2. File uploads / blob / S3
The judgment call is not how to call a storage SDK. It is why a file never belongs as a database BLOB column here.
Open
3. Background work with RabbitMQ
The same conceptual lens as Redis and file storage: recognize when work does not belong inside the request and response cycle, without installing anything today.
Open
4. Docker & Compose
Judge Docker the same conceptual way as Redis or RabbitMQ: where it solves a real environment problem, and where it stops mattering for this course.
Open
5. WebSockets / Socket.IO
The judgment call: which features actually need a live push channel versus which just need a refetch or a short poll.
Open
6. Postman + VS Code debugging
These are everyday tools for isolating whether a bug is frontend, backend, or a contract mismatch, before touching any code.
Open
7. Nest testing (unit + e2e / Supertest)
Before shipping milestone P4, learn how graders and CI assert HTTP behavior without clicking a UI.
Open
8. Performance (indexes, lean queries, pagination)
This connects directly to the challenge topics ahead. Recognize the patterns here so they are easy to diagnose in the challenges.
Open
9. Lint, format, Nest pitfalls
Beyond generic JavaScript and TypeScript lint rules, Nest has framework-specific pitfalls that lint rules alone will not catch.
Open
10. Challenge: JWT + RBAC hole
This challenge reuses the authentication and authorization habits from earlier weeks: the difference between not authenticated and not authorized, and the role guard pattern.
Open
11. Challenge: missing index / slow list
This reuses the performance judgment from earlier in this week: recognizing the missing-index smell on a slow, filtered, frequently used endpoint.
Open
12. Challenge: broken pagination / soft-delete leak
Combines pagination correctness with a realistic soft-delete pitfall.
Open
13. Code review & feedback
Use the same checklist mindset from this week when reviewing a teammate Nest PR — migrations, guards, DTOs, and contracts.
Open
14. Notes API — Ship slice milestone
Replaces the old all-in-one hands-on topic. Capstone coding, not a PLATFORM.md essay.
Open

End-of-week mini-project · practice only

Notes API — Ship slice (P4)

Compose, index migration, attachment metadata, and a NotesEventsPublisher seam.

Definition. Week 4’s mini-project is Notes P4: a shippable ops + platform slice with automatic validation.

In simpler words. Finish Notes so a teammate could run Compose and hit attachments + events. Prove with the P4 grader.

Deliverables

docker-compose.yml with Postgres
Index migration for list filters/sorts
Attachment upload + in-memory event publisher on create

Acceptance checklist

- [ ] Read nest-testing topic before final submit
- [ ] pnpm course:validate-milestone be-notes-p4 is green
- [ ] Open topic be-notes-p4 for full ship checklist
- [ ] Judgment notes for Redis/Rabbit stay short and tied to real features

Tips

P4 is Compose + code seams — not a PLATFORM.md essay alone.

Open related topic Open example / docs