Alexandre Brihaye developed a unified OnOff action callback system for the SiliconLabsSoftware/matter_extension repository, focusing on simplifying event handling for plug on/off actions. He refactored the OnOffPlugManager and AppTask components, consolidating separate initiation and completion callbacks into a single action callback. This C++-based redesign reduced callback fragmentation and minimized potential race conditions, resulting in more reliable plug control and streamlined future maintenance. Alexandre applied embedded systems and IoT expertise throughout the process, validating the changes with standard build and test workflows. The work demonstrated thoughtful modularization and improved the maintainability of the codebase without introducing new bugs.