RefactorLabs

the catalog

Every course, and what you'll build.

90 courses across JavaScript, TypeScript, React, Next.js, Vue and Svelte. Each one includes a weekly one-on-one call, code review on everything you submit, and lifetime access to the material.

15 courses in TypeScript

  • TS+Beginner

    Your First Typed File

    Add types to JavaScript you already wrote, and see the compiler catch a real bug.

    • Fundamentals
    • Annotations
    • Compiler
    3 weeks3 1-on-1 calls

    £4.99

  • TS+Beginner

    Interfaces, Unions and Narrowing

    Model the states your data can actually be in, then let the compiler prove you handled them.

    • Interfaces
    • Unions
    • Narrowing
    4 weeks4 1-on-1 calls

    £12.88

  • TS+Intermediate

    Generics You Can Actually Read

    Write reusable typed functions without producing signatures nobody can decipher.

    • Generics
    • Constraints
    • Inference
    4 weeks4 1-on-1 calls

    £19.88

  • TS+Advanced

    Conditional and Mapped Types

    Compute types from other types, and keep the result maintainable.

    • Conditional types
    • Mapped types
    • Template literals
    5 weeks5 1-on-1 calls

    £47.88

  • TS+Advanced

    Inference and Where It Gives Up

    Understand how types get guessed, so you know which annotation actually fixes the error.

    • Inference
    • Widening
    • as const
    3 weeks3 1-on-1 calls

    £19.88

  • TS+Intermediate

    Declaration Files and Other People's Types

    Work with a dependency whose types are wrong, missing or actively hostile.

    • Declaration files
    • Augmentation
    • Dependencies
    3 weeks3 1-on-1 calls

    £12.88

  • TS+Beginner

    tsconfig, Strictness and Migration

    Turn strict mode on in a real codebase without stopping all other work for a month.

    • tsconfig
    • Strict mode
    • Migration
    4 weeks4 1-on-1 calls

    £12.88

  • TS+Intermediate

    Testing Types, Not Just Code

    Assert that your types behave, so a refactor cannot quietly loosen them.

    • Type tests
    • expect-type
    • Regression
    4 weeks4 1-on-1 calls

    £19.88

  • TS+Advanced

    Monorepos and Project References

    Make a multi-package repository build fast and stay type-safe across boundaries.

    • Monorepo
    • Project references
    • Build graph
    10 weeks10 1-on-1 calls

    £117.88

  • TS+Intermediate

    Typed React Components

    Type props, hooks and generic components without resorting to `any` at the hard parts.

    • React
    • Props
    • Hooks
    6 weeks6 1-on-1 calls

    £47.88

  • TS+Intermediate

    One Contract, Client to Server

    Define the API once and have both sides break at compile time when it changes.

    • API contracts
    • Validation
    • Schemas
    7 weeks7 1-on-1 calls

    £67.88

  • TS+Intermediate

    Typed Node Services

    Type the messy edge of a backend: requests, config, environment and database rows.

    • Node.js
    • Backend
    • Validation
    6 weeks6 1-on-1 calls

    £47.88

  • TS+Intermediate

    Building a Component Library

    Design components other teams can use without reading your source code.

    • Design systems
    • Polymorphism
    • Accessibility
    8 weeks8 1-on-1 calls

    £77.88

  • TS+Advanced

    Inside the TypeScript Compiler

    Use the compiler as a library: parse, walk and rewrite code programmatically.

    • Compiler API
    • AST
    • Codemods
    9 weeks9 1-on-1 calls

    £107.88

  • TS+Advanced

    Capstone: Ship a Typed Library to npm

    Design, document, publish and version a package that strangers can depend on.

    • Capstone
    • npm
    • Versioning
    12 weeks12 1-on-1 calls

    £147.88