Getting Started: TypeScript Interview Questions

Technical interviews for TypeScript roles test much more than basic syntax; they require a concrete understanding of how the language, the type system, and the underlying JavaScript engine actually behave. This course prepares you for those interviews by walking through the core concepts that consistently appear in technical assessments. You will start with the mechanics of the type system, including compilation, type inference, widening, and the strict differences between any, unknown, never, and void. From there, we cover execution fundamentals like hoisting, the temporal dead zone, scope shadowing, and the exact behavior of var, let, and const. We also tackle type coercion, equality, and modern operators like nullish coalescing and optional chaining.

Next, you will explore how to model data using interfaces, type aliases, and object types, paying close attention to reference semantics, index signatures, and destructuring. The course then walks through arrays, tuples, and the nuances of enums and const enums, before examining function parameters, overloads, closures, and the often-confusing behavior of this. You will learn how to safely handle type narrowing using typeof, instanceof, discriminated unions, and custom type guards, followed by a practical introduction to generic functions and constraints. Finally, we cover object-oriented programming via classes and the prototype chain, and break down asynchronous execution by detailing the event loop, promises, async / await, and the distinction between microtasks and macrotasks. The course wraps up with compiler basics, ES modules, the satisfies operator, and common pitfalls to avoid during your interviews.