Sr. Software Engineer - CTJ - Secret

Job ID: 200044821Posted: 2026-07-29Location: United States, Washington, RedmondSalary: USD $119,800 - $234,700 per yearEmployment type: Full-TimeWork site: 3 days / week in-officeRole type: Individual ContributorTravel: Less than 25%Profession: Software EngineeringDiscipline: Software EngineeringCompany: MicrosoftOverviewStep into the future of connectivity with the Microsoft 365 Substrate First Mile Networking team, where bold innovation meets massive scale. We shape the networking infrastructure that fuels Substrate and COSMIC—critical platforms behind Microsoft’s most impactful productivity experiences like Copilot, Outlook, Teams, and SharePoint. We tackle some of the most complex distributed systems challenges in the industry, driving performance, reliability, and intelligence across global networks. With millions of users depending on our solutions daily, our contributions resonate across the entire Microsoft ecosystem.As a Sr. Software Engineer in the Microsoft 365 Substrate First Mile Networking team, you will design and implement scalable networking solutions for the Microsoft 365 Substrate and the COSMIC (container-based) platforms. Our product offerings extend to sovereign cloud environments, and your clearance will allow you to work in specialized environments focused on the unique needs of a critical customer base. You will design and optimize first-mile connectivity systems to ensure low-latency, high-reliability access to productivity services. Additionally, you will analyze production service telemetry to identify and implement continuous improvements. This opportunity will allow you to work on foundational infrastructure that powers Microsoft’s most critical services. It will provide an opportunity to solve real-world problems at massive scale with global impact, on a team that values innovation, autonomy, and technical depth.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.ResponsibilitiesCollaborates with appropriate stakeholders to determine user requirements for a scenario.Drives identification of dependencies and the development of design documents for a product, application, service, or platform.Creates, implements, optimizes, debugs, refactors, and reuses code to establish and improve performance and maintainability, effectiveness, and return on investment (ROI).Leverages subject-matter expertise of product features and partners with appropriate stakeholders (e.g., project managers) to drive a workgroup's project plans, release plans, and work items.Acts as a Designated Responsible Individual (DRI) and guides other engineers by developing and following the playbook, working on call to monitor system/product/service for degradation, downtime, or interruptions, alerting stakeholders about status and initiates actions to restore system/product/service for simple and complex problems when appropriate.Proactively seeks new knowledge and adapts to new trends, technical solutions, and patterns that will improve the availability, reliability, efficiency, observability, and performance of products while also driving consistency in monitoring and operations at scale.Other:Embody our company's Culture and Values.QualificationsRequired Qualifications:Bachelor's Degree in Computer Science or related technical field AND 4+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or PythonOR equivalent experience.Other Requirements:Security Clearance Requirements: Candidates must be able to meet Microsoft, customer and/or government security screening requirements as required for this role. These requirements include, but are not limited to the following specialized security screenings:The successful candidate must have an active U.S. Government Secret Security Clearance. Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. Failure to maintain or obtain the appropriate clearance and/or customer screening requirements may result in employment action up to and including termination.Clearance Verification: This position requires successful verification of the stated security clearance to meet federal government customer requirements. You will be asked to provide clearance verification information prior to an offer of employment. Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter. Citizenship & Citizenship Verification: This position requires verification of U.S. citizenship due to citizenship-based legal restrictions. Specifically, this position supports United States federal, state, and/or local United States government agency customer and is subject to certain citizenship-based restrictions where required or permitted by applicable law. To meet this legal requirement, citizenship will be verified via a valid passport, or other approved documents, or verified US government Clearance.Preferred Qualifications:Master'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 Bachelor'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 Python OR equivalent experience. Understanding of networking technologies, protocols, and concepts such as TCP/IP, DNS, load balancing, and service mesh architectures.Understanding of network security technologies such as firewalls, DDoS mitigation tools, and proxies.Expertise with Linux networking and/or container networking technologies such as Cilium.Experience with cloud platforms (Azure preferred) and microservices.Proven ability to work in a fast-paced, collaborative environment.Software Engineering IC4 - The typical base pay range for this role across the U.S. is USD $119,800 - $234,700 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 $160,200 - $261,000 per year. Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here:This 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.