SeniorFullstackEngineer(BackendFocus)

Proxima is the Conversion Intelligence platform for ecommerce. Powered by a proprietary Commerce Graph spanning 73M+ buyers across 2,000+ ecommerce brands, we help teams understand what actually drives conversion across the broader market, and turn those signals into clear creative direction. Our data is deterministic (real names, emails, and addresses from actual orders, not inferred from sessions), granular (full SKU-level receipt data), and point-in-time (timestamped history that enables recency scoring and ML without look-ahead bias). Headquartered in New York City, we're a team of operators, builders, and ecommerce veterans solving the hardest problems in modern customer acquisition. About the Role We're looking for a Senior Full Stack Engineer to help build the AI-driven products at the core of our platform. You'll work directly with our proprietary dataset — real-time, anonymized cross-brand transaction data — to build the services, agents, and tools that power Conversion Intelligence. This is a full stack role with a center of gravity in the backend. The majority of your work will be backend services, data systems, AI orchestration, and APIs — but you'll also own the UIs that surface this work to users, so you should be genuinely comfortable across the stack. If you thrive in fast-moving environments and are energized by pushing the limits of AI-assisted development, we'd love to talk. What You'll Own - Design, build, and document backend services and APIs that power our AI-driven products - Develop end-to-end features across AI agent interfaces, orchestration layers, and developer-facing tools - Query, model, and manage relational databases — own the data layer, not just consume it - Build and scale the systems that turn cross-brand transaction data into product - Ship responsive, clean UIs in TypeScript and React where the product needs them - Own projects from architecture to deployment in an agile, high-velocity environment - Collaborate cross-functional