Worked on the Automattic/harper repository to improve accessibility activation across macOS AppKit and Electron-based desktop applications. Addressed activation failures on macOS 15.7.x by implementing robust error handling for unsupported AX attributes, introducing an Electron-specific fallback using AXManualAccessibility, and enhancing text-metrics validation to accurately map lint spans to leaf AXText nodes. These changes enabled underlines and suggestions in both native and Electron apps such as TextEdit and Slack. The solution was developed using Rust, with a focus on desktop application and macOS development, and was consolidated in a single feature commit that resolved a longstanding accessibility issue.