Principal Software Engineer, Amazon Traffic Engineering

At Unified Auth, we build the trust infrastructure that secures how every service, employee, and AI agent at Amazon proves who they are and what they are allowed to do. Our systems operate as Tier 0 infrastructure across more than 50,000 applications, authenticating and authorizing billions of interactions across Amazon's service graph while absorbing evolving security, privacy, and compliance demands so builders can focus on their business logic. We are the single SDK and fabric behind CloudAuth, the product that lets teams enforce least privilege access at SDO scale. We are seeking a Principal Software Development Engineer to own the SDK and builder experience through which the entire company adopts Unified Auth. You will set the multi-year technical strategy and architecture for a single SDK spanning six languages and the end-to-end builder journey, and you will define how Amazon does authentication and authorization in the emerging era of AI agents. You will have significant autonomy to shape the technical direction across our platforms, focusing on: • Designing SDKs and developer experiences adopted with near zero friction by thousands of teams and their coding agents • Delivering resilience so authentication is never the reason a service is slow or unavailable, even at tens of millions of transactions per second • Establishing verifiable agent identity and per action authorization for agentic workloads • Aligning our trust context model with emerging industry standards and with AWS • Pioneering secure by default platforms and AI native on-boarding Key job responsibilities Technical Architecture and Innovation • Design and evolve the client SDK and builder experience across six languages and multiple runtimes • Architect static stability so services retain a 24-hour operating runway when the auth service is impaired • Build verifiable, composite agent identity and per action authorization for agentic workloads • Align the SDK and CloudAuth with industry standards such as OAuth, OIDC, and agent identity specifications • Drive high-performance systems meeting tier 0 availability and low latency requirements • Lead adoption of proven and emerging technologies to reduce cost and complexity Technical Leadership • Provide architectural guidance across many teams and set the engineering standard through designs and reference implementations • Partner with senior leadership on technical strategy and roadmap • Mentor engineers and leaders to elevate technical excellence • Collaborate with Principal Engineers and partner organizations, including AWS • Lead complex technical initiatives spanning multiple organizations Impact and Scope • Shape how every human, service, and agent interaction at Amazon is authenticated and authorized • Remove undifferentiated security effort for thousands of builders Influence technical direction across the organization and the broader industry • Retire legacy infrastructure and modernize the platform without disrupting live traffic A day in the life You spend your day at the intersection of deep technical work and broad influence. You might review an SDK design for a new language, debug a static stability edge case with an engineer, and then shift to aligning two partner teams and AWS on how agent identity should propagate across the call graph. You write and review the designs and reference implementations that set the standard, you clarify ambiguity for teams navigating a fast-evolving landscape, and you make the architectural calls whose impact reaches the entire company. You are hands on where it matters and a force multiplier everywhere else, leaving Amazon's trust infrastructure simpler, safer, and easier to build on than you found it.