Manuals / TypeScript / Ch 10

E · Job-readyAdvanced35 min read

10. Checkpoint B — Typed project ready

TypeScript · 44 pages source format

Final gate: a strictly typed project with generics, utilities, typed API, and migration complete enough to demo in an interview.

What you'll learn

  • Interview TS topics
  • Portfolio readiness

Pass criteria

  • strict: true, typecheck + tests green in CI or locally
  • Domain models + discriminated union (FetchState/Result)
  • Generic ApiResponse or equivalent in use
  • Utility types (Pick/Omit/Partial) — not hand-duplicated shapes
  • API responses typed with guard or Zod validation
  • Migration plan step 4+ complete (main + tests in TS)
  • Can explain generic <T> and narrowing in 2 minutes

Do this now

Verify every item. Fix gaps this week.

Clear?

Interview drill

Common questions: any vs unknown, type vs interface, what strictNullChecks fixes, how infer works, example discriminated union.

Do this now

Record 5-minute answers. Demo typed project in VS Code — hover types, go to definition.

Clear?

What next

Apply TS to test automation (Playwright/Cypress typed page objects), React/Vue with TS, or Node backend. This library has paths for each.

Do this now

Write 3 next-skill goals for 90 days.

Clear?

Checklist