Senior Fullstack Engineer (Backend Focus)

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 RoleWe'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 OwnDesign, build, and document backend services and APIs that power our AI-driven productsDevelop end-to-end features across AI agent interfaces, orchestration layers, and developer-facing toolsQuery, model, and manage relational databases — own the data layer, not just consume itBuild and scale the systems that turn cross-brand transaction data into productShip responsive, clean UIs in TypeScript and React where the product needs themOwn projects from architecture to deployment in an agile, high-velocity environmentCollaborate cross-functionally to ship high-impact features quicklyStay current on modern AI development practices and toolingQualifications6+ years of professional software development experienceStrong backend proficiency in TypeScript, with solid working knowledge of SQL and relational database designDemonstrated experience building or integrating AI-powered applications — agents, orchestration, or LLM-backed systemsProven track record in startup environments — you've shipped fast and worn multiple hatsComfortable owning projects independently in high-velocity environmentsWorking proficiency in React and the ability to build production UIs when the work calls for itDaily use of AI-assisted coding tools (Cursor, GitHub Copilot, Claude Code, etc.) — this is a requirement, not a nice-to-haveBachelor's degree or higher in Computer Science, Engineering, or a related fieldNice to HaveProficiency in PythonExperience with AI agent frameworks, orchestration tools, or embeddingsBackground in data engineering (ETL, dbt, Airflow, etc.)Familiarity with cloud platforms (AWS, GCP, Azure) and containerization (Docker, Kubernetes)Experience writing production-grade CSS/SCSSLocationOpen to remote candidates based in the U.S. or hybrid candidates in New York City, with a preference for NYC.Work Authorization: Must be authorized to work in the U.S. without sponsorship. Visa transfers may be considered on a case-by-case basis.Why ProximaWork on one of the most differentiated data assets in consumer techHigh ownership and accountability — drive projects end-to-end and make decisions that actually matterLean team where your contributions are visible and your voice carries weightHighly cross-functional — work closely with product, data, growth, and leadershipHybrid setup in our NYC office with a collaborative in-person culture, plus quarterly team events in and out of the officeBenefits & PerksCompetitive base salary and meaningful equityComprehensive medical, dental, and vision coverageHSA and FSA options401(k)12 weeks of fully paid parental leaveUnlimited PTOSummer Fridays from July 4th through Labor DayMental health and wellness support through Talkspace, Health Advocate, and One MedicalCommuter benefits$1,000 annual learning & development stipendQuarterly team events, both in and out of the officeHow To ApplySubmit your application through our Ashby job board. We review every application and will reach out directly if there's a potential fit.Proxima is an equal opportunity employer. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We're committed to building a team that reflects a range of backgrounds, perspectives, and experiences, and we evaluate all candidates on merit.Compensation Range: $150K - $190K