Software Development Engineer, Identity Services

Identity Services are the guardians of Amazon's most sacred asset - customer trust! The stakes for us at Amazon have never been greater as Amazon expand more into customers' daily lives. We enable Amazon businesses to scale by providing secure authentication and authorization solutions in the most possible friction-less manner. We are moving towards the vision where our clients no longer have to choose between sophisticated security and user convenience. Our guiding principle for adaptive authentication is simple; if we suspect a risk in our multiple risk-layer checks, which run quietly in the background, we will deploy the most secure and appropriate available solution, and if we do not, we will let the customer use Amazon unimpeded.

We"re seeking a Software Engineer to join our Identity Services team, responsible for authentication and session management systems that serve millions of customers across web, mobile, and device platforms.

Key job responsibilities

• Design and implement secure authentication and authorization systems using bearer token schemes and session management protocols
• Build and maintain high-performance validation services with strict latency requirements (sub-10ms response times)
• Develop intelligent authentication systems that balance security with user experience, reducing unnecessary re-authentication friction
• Implement security features including token binding, risk evaluation, and fraud detection mechanisms
• Collaborate with security teams to detect and prevent account takeover attempts and cookie theft
• Work on token lifecycle management including creation, validation, exchange, and invalidation across multiple platforms

About the team

AuthZero is the team responsible for authentication and session management across Amazon"s platform. We own critical services including Aztec Service for token management and work closely with the Session Service team. Our systems handle token creation, validation, exchange, and invalidation for web, mobile apps, devices, and Login with Amazon (LWA). We"re at the forefront of reducing authentication friction through Intelligent Authentication while maintaining robust security. The team tackles complex challenges including cookie theft detection, risk-based authentication, and building scalable systems that process authentication requests with sub-10ms latency at massive scale.