TypeScript Core (Interview Prep)
A structured roadmap of the TypeScript fundamentals that matter most in frontend interviews. Start top-to-bottom.
Series: TypeScript Core
Roadmap (15)
Browse all TypeScript posts →- 1
TypeScript: types vs interfaces (When to Use Which)
A deep, interview-ready guide to TypeScript types vs interfaces: extension, unions, intersections, declaration merging, and practical patterns for real codebases.
~22 min - 2
TypeScript Generics: Basics, Constraints, and Real Patterns
A deep, interview-ready guide to TypeScript generics: why they exist, how inference works, constraints (extends), default generics, and practical examples used in real codebases.
~24 min - 3
TypeScript Narrowing & Discriminated Unions (Interview-Ready)
A deep, interview-ready guide to narrowing in TypeScript: typeof, in, instanceof, user-defined type guards, and discriminated unions for safe, expressive code.
~24 min - 4
TypeScript Utility Types: Pick, Omit, Partial, Record (Practical Guide)
A deep, interview-ready guide to TypeScript utility types: Pick/Omit/Partial/Required/Readonly/Record, common patterns, and how to avoid over-complicating types.
~22 min - 5
any vs unknown vs never (Interview-Ready)
How to choose any/unknown/never, why unknown is safer, and how never appears in narrowing and exhaustive checks.
2 min read - 6
Type Guards & Narrowing Patterns
How narrowing works in TypeScript: typeof/in, custom type guards, assertion functions, and practical patterns for safer code.
1 min read - 7
The `satisfies` Operator (Why It’s a Big Deal)
How `satisfies` helps validate shapes without losing literal types, and why it often beats `as const` and type annotations.
1 min read - 8
Conditional Types + infer (Interview Essentials)
Understand conditional types, infer, and how TypeScript extracts types from functions/promises/arrays.
1 min read - 9
Declaration Merging & Module Augmentation
How TypeScript merges interfaces, augments modules (like Express/NextAuth), and why this matters in real codebases.
1 min read - 10
tsconfig.json: The Settings That Matter
A practical guide to TS compiler options interviewers ask about: strict, noImplicitAny, lib, moduleResolution, jsx, and incremental builds.
1 min read - 11
Enums vs Union Types (and const enums)
When to use enums, when to prefer string unions, and what const enums change.
1 min read - 12
Typing React Components in TypeScript (Practical Patterns)
Props, children, event handlers, generics in components, and common TS + React pitfalls interviewers ask about.
1 min read - 13
Mapped Types, keyof, and Template Literal Types (Interview-Ready)
How keyof + mapped types work, and how template literal types unlock powerful typed APIs.
1 min read - 14
Advanced Generics: Overloads, Inference Tricks, and Variance
Interview-focused advanced generics: overloads, inference patterns, variance basics, and designing ergonomic typed APIs.
2 min read - 15
Type-Level Testing & API Design Patterns
How to validate TypeScript types, design safer APIs, and avoid unsafe assertions—interview-ready patterns.
2 min read