Lars worked on the lifinance/types repository, delivering an API simplification by making the Action.slippage property optional within the TypeScript interface. This change reduced boilerplate for developers and allowed for more flexible action creation without sacrificing type safety or backward compatibility. Lars focused on interface design and API ergonomics, ensuring that the updated TypeScript definitions continued to meet existing requirements while streamlining the developer experience. The work was managed through commit-driven development using Git, and no major bugs were documented during this period. Overall, the contribution demonstrated a targeted, well-scoped improvement in TypeScript-based API usability and maintainability.