Microsoft AI (MAI) is seeking experienced Platform Engineers to help build the next wave of capabilities of their personal AI, Copilot. This role is part of Microsoft's ambitious vision to build systems with true artificial intelligence across agents, applications, services, and infrastructure. As a Platform Engineer, you'll be responsible for building APIs that support finetuning and deploying the core experience of Copilot, while collaborating with Product Management, Design, and AI Research teams. The position requires technical prowess in backend technologies, distributed systems, and cloud infrastructure, with a focus on building scalable AI platform services. You'll work in a hybrid environment (3 days in office) in the Seattle area, contributing to Microsoft's mission of empowering every person and organization on the planet to achieve more. The role offers competitive compensation ($137,600 - $267,000) and comprehensive benefits, making it an excellent opportunity for experienced engineers passionate about AI and large-scale systems.