• Converted existing JavaScript code, including React Context state management and JSX components, to TypeScript. Strong typing and best practices improved error handling, future-proofing the code and preventing unpredictable bugs.• Reconfigured Babel and Jest to add JSX and TypeScript compatibility to unit tests, re-enabling 81% of defective tests.• Added additional Jest environments and module name wrapping to enable parsing of files with non-JS imports and DOM-based APIs, increasing the number of testable files.• Fixed majority of deprecation warnings, adding longevity and cleaning up outmoded dependencies. Migrated app from Node 16.13 to Node 19+, maintaining 100% app functionality in the process. Resolved majorly out-of-date Electron install, updating 9 versions while maintaining other dependencies to ensure changes were non-breaking.• Tackled known bugs and technical debt: fixed terminal component by tracking down event listener cleanup issue that caused duplicated input, and resolved bug that occurred when deleting describe blocks in accessibility component. • Contributed documentation, adding explanations and component hierarchy visualizations to help onboard new devs.• Built and packaged Electron application, creating new executables for Windows, Mac and Linux with Electron Builder.