You migrated to TypeScript. You renamed the files. You installed the types. You pat yourself on the back.

Then six months later, a senior dev reviews your PR and politely points out that your codebase is basically JavaScript with extra steps. any scattered like confetti. Type assertions used as a fire extinguisher. Interfaces that technically exist but never do any work.

Sound familiar? Let’s fix that — without turning your codebase into an academic exercise.