Worked on the marimo-team/marimo repository to address a critical issue in the useNonce React hook, focusing on improving reliability in nonce-based flows. Tackled a stale closure bug by implementing a functional state update, ensuring that nonce values increment correctly even during rapid successive calls. Enhanced the robustness of the codebase by adding comprehensive tests that validated useNonce behavior across a variety of scenarios, thereby reducing race conditions and mitigating flaky tests. Utilized JavaScript and TypeScript for front end development and testing, contributing to improved concurrency safety and overall stability in authentication and state management within the project.