Salim Toubal focused on improving reliability and maintainability for MetaMask’s metamask-mobile repository, specifically targeting the ERC20 token sending flow on custom networks. By introducing optional chaining in TypeScript, Salim prevented token address access errors that previously disrupted transactions on non-standard networks. He also restructured unit tests to use an enabled network map, clarifying test data and enhancing test reliability. Working primarily with React and TypeScript, Salim’s contributions addressed two critical bugs, reducing user-facing errors and improving transaction success rates. The work demonstrated a thoughtful approach to front end development and unit testing, with depth in both code quality and test coverage.