Worked on the pmndrs/zustand repository to enhance TypeScript ergonomics for state management library users by publicly exposing the ExtractState type helper. This involved moving its definition to a core file, vanilla.ts, and providing comprehensive documentation along with an example to demonstrate how developers can infer state types outside of store declarations. The update, implemented using both JavaScript and TypeScript, improved type inference capabilities and reduced boilerplate in TypeScript projects. By focusing on library development and state management, the work delivered measurable improvements to developer experience, making it easier for Zustand users to manage and infer state types efficiently.