The One Engineering System (1ES) team within Microsoft's Cloud and AI division is seeking a Senior Software Engineer to contribute to their next-generation developer services and tools. This role focuses on designing and implementing software services that support thousands of Microsoft engineers and the broader DevOps market. The position involves working on large-scale distributed services for build and test systems, which are crucial to Microsoft's internal engineering workflows. The team values Test Driven Development, Continuous Integration, Continuous Delivery, and maintains a Culture of Experimentation and Lean Agile methodologies. The role requires collaboration with distributed teams, designing highly available systems, and experience with cloud architectures. The position offers a hybrid work environment with up to 50% work from home flexibility and requires 0-25% travel. The ideal candidate should have strong experience in languages like C#, PowerShell, Java, JavaScript, or Python, and be passionate about software engineering and customer-focused product development. The role provides an opportunity to shape the future of software development both at Microsoft and in the industry while working with cutting-edge technologies and large-scale systems.