TypeScript in 30 days: how to translate a project without pain

TypeScript is no longer just an alternative to JavaScript — it is an industry standard.
Today, almost all serious projects in the front-end ecosystem are built on TS. Facebook, Microsoft, Airbnb, Shopify — all have switched or are switching to strict typing.

The question is no longer "is it necessary?", but "how to migrate quickly and painlessly?". Let's take a look at the migration plan for 30 days - with a step-by-step strategy, checklists and pitfalls.

Why has TypeScript become the standard?

• Code predictability: fewer bugs in production.

• Development speed: autocomplete and IDE prompts.

• Teamwork: it's easier to understand someone else's code.

• Ecosystem: React, Angular, NestJS are focused on TS.

📊 According to the State of JS 2025 study — 80% of developers use TypeScript daily.

30-day migration plan ⏳

Week 1 — Preparation

• Set typescript and ts-node.

• Add tsconfig.json with basic settings.

• Enable strict mode ("strict": true).

• Configure the build (Webpack / Vite / esbuild).

👉 Goal: the project is being assembled, but the code is still in JS.

Week 2 - Soft start

• Rename the first files from .js to .ts.

• Start with utilities and services.

• Use any, but gradually replace it.

• Connect ESLint + TS plugins.

👉 Goal: part of the code is already on TS, no pressure.

Week 3 — Deep Integration

• Translate the main modules: components, API clients.

• Add interfaces and DTO types.

• Turn on strictNullChecks, noImplicitAny.

• Set @types/... for libraries.

👉 Goal: at least 60% of the code is typed.

Week 4 — Final and Quality Control

• Translate the remaining modules.

• Replace the temporary any with real types.

• Turn on noUncheckedIndexedAccess.

• Add a CI pipeline to check the types.

👉 Goal: 100% code in TS + strict rules in CI.

Comparison: JavaScript vs TypeScript

Migration tools

• ts-migrate — automatic file conversion.

• babel-plugin-transform-typescript — gradual integration.

• typescript-eslint - linting and style control.

• ts-prune — search for unused types.

• GraphQL Code Generator — auto-generation of types from the schema.

Real-life cases

• Airbnb: the number of bugs in runtime fell by 38%.

• Slack: migration took six months, but accelerated feature integration.

• Shopify: TS has become mandatory for frontend teams.

Pitfalls ⚠️

• It's easy to get stuck on any → use unknown and specify step by step.

• Third-party libraries without types → write d.ts files.

• Team resistance → show the benefits on real cases.

Summary 🚀

TypeScript is no longer a trend, but a reality. Migration in 30 days is real if you move gradually.
In a month, you will receive: clean and predictable code, fast development, and confidence in the scale of the project.

We have an active Telegram channel, where we discuss cool ideas, share experiences and analyze tasks together — learning becomes not only useful, but also fun. Join us if you're not there yet.

Try to translate one of your small pet projects to TypeScript in 7 days and share your experience in the comments!