OverviewWe are seeking a Principal Software Development Engineer to lead the design and development of the Search & AI Platform at Microsoft Bing. As the core platforms underpinning web-index serving, big data processing, AI inference, and LLM grounding, the system interacts with hundreds of millions of users worldwide every day. We are looking for a passionate and experienced platform engineer to work with us to build the new generative search engine for Bing, leveraging heterogenous hardware, hybrid retrieval, and agentic workflow. In this role, you will: Architect and implement scalable distributed systems foundational for Search & AI platform. Innovate the modern search retrieval system with cutting edge vector index engineLead technical vision and execution for building generative search that acts autonomously within a large-scale infrastructure. Optimize data access patterns, compute workflows, and storage strategies to meet rigorous SLA requirements across offline and online workloads. Work closely with cross-functional teams (AI, infra, product) to translate research advances into production-grade systems. Mentor and grow a high-performing engineering team focused on long-term platform evolution. Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond. Starting January 26, 2026, Microsoft AI (MAI) employees who live within a 50- mile commute of a designated Microsoft office in the U.S. or 25-mile commute of a non-U.S., country-specific location are expected to work from the office at least four days per week. This expectation is subject to local law and may vary by jurisdiction.ResponsibilitiesArchitect, design, and implement high-performance solutions to enhance Search & AI platform. Technically lead the development and scaling of our distributed services, ensuring robustness, performance, and reliability. Collaborate with various teams to transform user requirements into actionable designs and systems. Provide technical leadership and mentorship to engineering teams, fostering a culture of excellence and innovation. Engage in the full software development lifecycle from conception to deployment, ensuring solutions meet high standards of quality and performance. Stay abreast of industry trends and apply best practices in software development and new technologies to drive improvementsQualificationsRequired Qualifications:Bachelor's Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR equivalent experience.Preferred Qualifications:Master's Degree in Computer Science or related technical field AND 8+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR Bachelor's Degree in Computer Science or related technical field AND 12+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR equivalent experience.3+ years of technical leadership experience of designing, coding, debugging and delivering large projects. Hands on experience in indexing technology and end to end search stackExpertise in Approximate-nearest-neighbor search is a plusExpertise in performance optimization and system architecture, particularly within large-scale processing environments is plus. Proven track record in designing and deploying scalable, distributed systems. Effective collaborator and communicator. #MicrosoftAI #Bing #SearchAIPlatform #SearchFundamental Software Engineering IC5 - The typical base pay range for this role across the U.S. is USD $142,800 - $274,800 per year. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $188,000 - $304,200 per year. Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here:https://careers.microsoft.com/us/en/us-corporate-payThis position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled.Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.