Software Development Engineer, AWS Cognito, AWS Cognito

AWS Cognito is one of the highest-profile services in AWS Identity: it handles billions of authentication requests for thousands of companies. Our job is to make sign-in so reliable that no one thinks about it. At this scale, that's a hard engineering problem. As agents, MCP tools, and non-human identities start acting on behalf of users, Cognito is building the solutions that let them sign in, carry scoped and verifiable authority, and be trusted the same way human identities are. If you want to help define what "agentic auth" means for AWS customers, this is the place. We are deliberately installing a startup culture inside a foundational AWS service: small teams that own problems end-to-end, short paths from idea to production, and a bias toward shipping and learning over waiting for permission. And we are AI-native in how we build—we don't just use AI tools; we build our own agents for code review, operational investigation, and CR scaffolding, and we engage AI first on most tasks. You get the ownership and pace of a startup with the scale, customers, and impact of core AWS. Key job responsibilities - Design, build, and operate highly available, low-latency authentication services that real customers depend on 24/7. - Own features end-to-end design, implementation, testing, deployment, and operations—for services in the Cognito User Auth space (sign-in, tokens, devices, and related data planes). - Raise the bar on operational excellence: measurable availability, latency, and security improvements, and automation that removes manual work. - Work AI-native: engage AI first, and build and extend the team's own agentic tooling for development, code review, and operational investigation. - Dive deep on ambiguous, production-impacting problems and drive them to a root cause and a durable fix. - Collaborate across AWS Identity teams and mentor other engineers. A day in the life The challenges SDEs solve for at Amazon are big and influence millions of customers, sellers, and products around the world. We are looking for individuals who are passionate about creating new products, features, and services from scratch while managing ambiguity and the pace of a company where development cycles are measured in weeks, not years.