Microsoft's Enterprise Search team is revolutionizing information access across Outlook, Teams, ODSP, and office.com. We're at the forefront of a paradigm shift, integrating AI and LLMs to power Microsoft 365 chat copilot experiences for billions of users globally. As a Senior Software Engineer, you'll be crucial in scaling our search infrastructure from 5000 to 50K shards, requiring fundamental changes across data and business layers. You'll join a diverse, global team working on next-generation search technology that powers M365 Chat Copilot, keeping Microsoft at the AI revolution's forefront. The role offers the chance to work with teams across Redmond, China, London, Germany, and India, focusing on technical excellence and open communication. You'll be responsible for designing, developing, and implementing innovative solutions while maintaining high performance and availability standards. This position combines technical depth with collaborative leadership, making it ideal for engineers passionate about large-scale distributed systems and AI integration.