How do you choose between an interface and a type alias in production TypeScript?

For exported libraries I consider diagnostics, augmentation expectations, and compatibility across releases. In an application, domain clarity matters more than enforcing a slogan such as 'interfaces for objects.' I avoid deep extends or intersection chains that make the resulting contract difficult to see. If composition produces conflicting properties, I define the intended type explicitly rather than relying on a cryptic never result. The public contract should remain understandable in an editor without requiring readers to expand several layers of type machinery.