Software Development Engineer III, Agentic Client Experience (ACE) - Builder Foundations

Builders across Amazon face challenges of building across multiple platforms in order to deliver value to our customers. Historically, this meant having to familiarize yourself with each of those platforms in order to submit the necessary changes that would support your product and project. ACE is working to simplify this through the use of agentic development practices that leverage tools for discovery, code generation, and automation to accelerate and improve the builder experience. Our work within Builder Foundations focuses on improving the tooling which is used every day to support the eCommerce efforts of Stores, Devices, and Other lines of business. As an SDE III, you will own the architecture and delivery of major system components end-to-end. You'll make technology choices that shape how Builder Foundations scales from thousands to tens of thousands of active workflows, design distributed data pipelines processing billions of events, and build the AI-powered features that transform Builder Foundations tools from a experiments into autonomous productivity platforms. You'll work across Java, Python, and TypeScript with deep expertise in RAG, DAG, MCP, ACP, agentic evaluations, AWS infrastructure (Lambda, DynamoDB, CDK), and data modelling for both relational and non-relational systems. You will lead technical design reviews, mentor engineers, and raise the engineering bar across the team. You'll partner directly with applied scientists on measuring adherence and effectiveness of agentic tooling and with product managers to translate ambiguous customer problems into scalable technical solutions. This is a team where an L6 engineer has outsized impact — we're small enough that your architectural decisions become the system, and high-visibility enough (S-team and VP-level goals) that leadership sees the results. The ideal candidate thrives in ambiguity, has a track record of delivering complex distributed systems in fast-moving environments, and gets energized by problems that sit at the intersection of big data, ML, and product. You're not just looking for a job — you're looking for a team where you can shape the technical direction of a product that's redefining how the advertising industry measures success. Key job responsibilities - Design and build scalable agent workflows for metrics collection and aggregation - Lead architecture decisions for ACE's calibration, report generation, and data processing systems spanning multiple pipelines across multiple AWS accounts - Own end-to-end delivery of major product features — from technical design through production launch — including real-time streaming attribution, AI-powered report generation, and new vertical measurement frameworks - Drive operational excellence across ACE's workflows: improve observability, eliminate silent failures, and build self-healing capabilities to meet builder SLAs - Mentor junior engineers, raise the bar on code quality through design reviews and CRs, and establish engineering best practices across the team - Partner with applied scientists and product managers to translate ML model requirements into production-grade systems that serve advertiser-facing measurement products A day in the life You might start your morning reviewing the overnight metrics collected on tooling runs, investigating why an adherence scenario's stats look anomalous. After the morning sync, you might pair with another software engineer to remove an unnecessary touchpoint in a workflow. In the afternoon, you lead a design review for a new plugin architecture that will improve code quality for generated DynamoDB queries. You close the day reviewing CRs from a teammate building LLM-powered code package scanning. Your work directly impacts how builders contribute to Amazon products across retail and beyond.

The ACE Team is part of the Builder Labs initiative to do research and development to bring cutting edge tooling to the software builders across