Isomorphic TypeScript refers to the use of TypeScript in frontend, backend, CLI tools, mobile, and desktop applications. Deepkit utilizes Isomorphic TypeScript by allowing code to be shared between different departments, such as frontend and backend. This includes sharing models, types, interfaces, validation logic, and business logic. By using TypeScript in as much code as possible, the development speed can be massively increased. Deepkit is designed to make the most of the advantages of Isomorphic TypeScript, enabling maximum productivity.