Software Development Engineer II, Seller Flex

Do you want to transform how sellers fulfill millions of orders worldwide? Seller Flex is Amazon's program that turns a seller's own warehouse into a fulfillment node—offering Prime badging and Amazon-orchestrated operations without moving inventory. As we expand into Japan and scale globally, we're seeking a Software Development Engineer II to tackle some of the most challenging problems in distributed systems, seller enablement, and fulfillment orchestration.

You'll work on systems that matter: designing for marketplace plurality so launching in new countries becomes a configuration change rather than a months-long effort, making seller state provably correct under partial failures, and building self-serve onboarding that scales without white-glove handholding. This role offers deep exposure to world-class operational standards, the chance to rearchitect fulfillment systems for global scale and agentic operations, and the opportunity to drive measurable business value for sellers across India, Europe, North America, Japan, and emerging marketplaces.

Key job responsibilities

• Design and implement scalable software solutions across the full development lifecycle—from scoping and architecture through deployment and operations—for Seller Flex's warehouse management, seller console, mobile app, and performance platforms
• Root cause and resolve high-impact seller issues by identifying architectural weaknesses and designing systems that prevent recurrence, including implementing distributed-systems patterns to ensure seller state consistency across services
• Drive continuous improvement in availability, latency, scalability, and maintainability of fulfillment systems, with emphasis on operational excellence and permanent fixes over short-term workarounds
• Collaborate across Amazon's Fulfillment Network teams to deliver marketplace-aware primitives, self-serve onboarding capabilities, and modernized monetization infrastructure that supports global expansion
• Participate actively in code reviews providing meaningful technical feedback, document system architecture and operational procedures, and mentor new team members on how Seller Flex software is constructed and operated

A day in the life Your day involves diagnosing and solving needle-moving seller issues such as why a newly onboarded seller is cancelling orders or why a return package is not picked up in a new geography. You'll spend time identifying architectural issues and designing for the future: turning ad-hoc reconciliation into proper distributed-systems patterns, or refactoring fee computation to support Japan's launch as a configuration change. You'll review and approve designs and code from teammates, establish operational standards that prevent issues before they occur, and collaborate with teams across the Amazon Fulfillment Network to ensure your solutions integrate seamlessly with the broader ecosystem.