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 enhancements. Alexandre validated the changes through standard build and test workflows, demonstrating skills in embedded systems, IoT, and modular event-driven design. The work improved maintainability and reliability, addressing core architectural concerns within the matter_extension codebase.