Do you want to protect how Amazon's workforce signs in and accesses critical systems every day? Amazon Foundational Security Services is looking for a Software Development Engineer II to build and operate the identity and authentication services that keep tens of thousands of employees secure and productive. You'll design and deliver distributed systems that handle real-time identity data sync, certificate issuance for corporate devices, and Kerberos authentication—solving problems where correctness and availability matter around the clock. This role offers rare breadth across the identity space in one team. You'll work on workforce sign-in and AWS access, near real-time directory sync, a corporate certificate authority, and Kerberos authentication. You'll balance building new capabilities on AWS with modernizing long-running core infrastructure, all through a security-first lens. If you're ready to turn well-understood business problems into simple, secure, and maintainable code while learning from every incident and mentoring others, we'd love to hear from you. Key job responsibilities - Design and build distributed services that handle authentication, authorization, and identity data synchronization, making sound tradeoffs between scalability, performance, and security - Deliver software features across the full lifecycle—from scoping and design through code, testing, deployment, and maintenance—while actively reviewing code and providing meaningful feedback to teammates - Participate in operational support including oncall rotation, monitoring and alarming, root cause analysis, and balancing new feature work against operational improvements to ensure services remain reliable - Work with identity and security technologies such as SAML, OpenID Connect, SCIM, LDAP, Active Directory, Kerberos, and X.509 certificates to solve real authentication and authorization challenges - Document how your services are constructed, tested, operated, and secured, and train new team members so they can confidently contribute and maintain the systems you build A day in the life Most days start with a short standup. You might spend the morning drafting a design doc for speeding up group membership sync for very large groups, then write and test the code with help from AI coding assistants. You review teammates' code and designs, offering constructive feedback. In the afternoon, you might pair with a newer engineer or meet with a partner team that depends on your identity data to understand their next requirements. During your oncall week, you triage alarms and tickets, identify root causes, and implement permanent fixes. About the team We're part of Amazon Foundational Security Services within Amazon Security. Our team builds and operates the identity and authentication services Amazon's workforce uses every day—from signing in and accessing AWS, to syncing identity data across downstream systems, to issuing certificates for corporate devices. We're based in Seattle and share oncall across the team, learning from every incident through structured post-incident reviews. Mentorship is part of the job here. Engineers get broad exposure to identity, security, and AWS, and grow by owning real problems end to end. Whether you're ramping up on our systems or taking on harder, more ambiguous challenges as you progress toward Software Development Engineer III, you'll find a team that supports your growth and values operational excellence alongside innovation. Diverse Experiences Amazon Security values diverse experiences. Even if you do not meet all of the qualifications and skills listed in the job description, we encourage candidates to apply. If your career is just starting, hasn’t followed a traditional path, or includes alternative experiences, don’t let it stop you from applying. Why Amazon Security? At Amazon, security is central to maintaining customer trust and delivering delightful customer experiences. Our organization is responsible for creating and maintaining a high bar for security across all of Amazon’s products and services. We offer talented security professionals the chance to accelerate their careers with opportunities to build experience in a wide variety of areas including cloud, devices, retail, entertainment, healthcare, operations, and physical stores. Inclusive Team Culture In Amazon Security, it’s in our nature to learn and be curious. Ongoing DEI events and learning experiences inspire us to continue learning and to embrace our uniqueness. Addressing the toughest security challenges requires that we seek out and celebrate a diversity of ideas, perspectives, and voices. Training & Career Growth We’re continuously raising our performance bar as we strive to become Earth’s Best Employer. That’s why you’ll find endless knowledge-sharing, training, and other career-advancing resources here to help you develop into a better-rounded professional. Work/Life Balance We value work-life harmony. Achieving success at work should never come at the expense of sacrifices at home, which is why flexible work hours and arrangements are part of our culture. When we feel supported in the workplace and at home, there’s nothing we can’t achieve.