Software Development Engineer II, Seller Flex

Are you passionate about solving complex fulfillment challenges at global scale? Join Seller Flex and help transform how third-party sellers fulfill Amazon orders worldwide. You'll architect systems that power warehouses across multiple countries, solving problems that directly impact millions of sellers and customers. From designing software-driven warehouse activation to building mobile-first operator experiences for Heavy & Bulky fulfillment, your work will drive measurable innovation in one of Amazon's fastest-growing programs.

This role offers a unique opportunity to become a domain expert in 3P fulfillment while rearchitecting core systems for global expansion and scale. You'll work at the intersection of marketplace platforms, warehouse operations, and inventory systems — simplifying architecture, solving high-impact seller problems, and establishing the technical foundation for launching new countries like Japan.

Key job responsibilities

• Design and implement scalable software solutions across the full development lifecycle, including architecture, code, testing, deployment, and maintenance, with focus on warehouse platform systems that enable fast, repeatable global expansion
• Actively participate in code review processes, providing meaningful technical feedback to peers and ensuring operational excellence through root cause analysis and permanent fixes for production issues
• Collaborate with cross-functional teams across the Amazon Fulfillment Network to architect solutions for inventory correctness, node lifecycle automation, and marketplace-aware eligibility systems
• Drive continuous improvement in availability, latency, scalability, and maintainability of fulfillment systems while balancing new feature development with operational priorities
• Identify and resolve architectural bottlenecks in catalog, SKU, and eligibility platforms, designing clean contracts between upstream marketplace systems and downstream order fulfillment

A day in the life You'll start by investigating needle-moving seller issues, perhaps an inventory mismatch between Seller Flex and a seller's warehouse records, or an edge case blocking warehouse activation in a new country. Mid-morning, you're reviewing a peer's design for making node configuration fully software-driven, offering feedback on idempotency and observability. After lunch, you're pairing with a teammate to refactor a mobile workflow that moves Heavy & Bulky operators off desktop terminals and onto the warehouse floor. You'll wrap up collaborating with teams across geographies on eligibility platform consolidation, ensuring the Japan launch stays on track.