TypeScript Communication & Stakeholder Relations 2

Question 1

A backend team asks why TypeScript interfaces are used instead of plain JavaScript objects in API contracts. What is the best explanation?

Accepted Answer

Interfaces provide compile-time shape guarantees and serve as living documentation for API contracts

Answer

TypeScript interfaces define the shape of data at compile time, giving teams a shared contract that IDEs can enforce and developers can reference as documentation.

Question 2

A stakeholder requests a feature that would require changing a public TypeScript API from returning `string` to returning `string | null`. What should you communicate first?

Accepted Answer

This is a breaking change that requires updating all consumers and coordinating a migration plan

Answer

Widening a return type to include `null` is a breaking change for any consumer not already handling null, requiring coordinated migration.

Question 3

During code review, a junior developer asks what `Readonly<T>` communicates to other team members. What is the correct answer?

Accepted Answer

It signals intent that properties should not be mutated after construction, enforced at compile time

Answer

`Readonly<T>` communicates immutable intent to developers and triggers compile-time errors if mutations are attempted, but has no runtime enforcement.

Question 4

A product manager wants to know why the team added strict TypeScript compiler options. How should you explain the business value?

Accepted Answer

Strict mode catches more bugs at compile time, reducing production defects and lowering maintenance costs

Answer

Strict compiler options like `strictNullChecks` and `noImplicitAny` surface more potential bugs during development, reducing costly production incidents.

Question 5

A cross-functional team wants to share TypeScript type definitions between a frontend and backend project. What approach best facilitates this communication?

Accepted Answer

Publish shared types as a versioned internal npm package so both teams consume the same source of truth

Answer

A shared, versioned npm package ensures both teams use identical types and version bumps signal breaking changes explicitly.

TypeScript Practice Test

TypeScript Practice Test

TypeScript Communication & Stakeholder Relations 2