Type Systems as Product Tools

TypeScript catches bugs at compile time that would otherwise reach your users. But its value goes beyond error prevention — strong types are a form of documentation that future team members (including yourself) will thank you for.

At Wrees, we use TypeScript's type system to encode product rules: invariants that the business logic requires. When a type error appears, it often reveals a product logic gap worth discussing.

This article explores how we've used TypeScript not just as a safety net, but as a product specification tool. The type definitions become a shared vocabulary between product thinking and implementation.