Senior Engineer - Backend Software Engineer

A growing consumer marketplace is hiring a Staff Backend Engineer to lead the architecture and evolution of its core platform and external APIs. The company is expanding an established product into new categories, markets, and distribution channels. You'll shape the technical foundation for that growth, make meaningful architectural decisions, and build systems that other engineers and partners depend on. This is a hands on individual contributor role with broad ownership and direct access to engineering leadership. You'll write production code, guide technical direction, and help other engineers deliver. Tech stack is open. We're looking for strong backend engineers with solid fundamentals, sound technical judgment, and the ability to learn quickly. Our environment includes Ruby on Rails, Node.js, Postgres, and AWS, but experience with our specific stack is not required. This is a full time position based in Manhattan, NYC. Monday through Thursday is in office work and Fridays are remote work. Lead architecture and technical direction for core backend systems and partner-facing APIs. Write production code and guide implementation across multiple backend engineers. Design data models and system boundaries that support complex business rules and new product categories. Ensure transactional correctness through concurrency controls, safe retries, recovery, and reconciliation. Evolve existing production systems through incremental migrations, testing, monitoring, and safe rollouts. Partner with engineering leadership, Product, and business stakeholders on priorities and technical tradeoffs. Own technical outcomes from initial design through launch and ongoing operation.8+ years of software engineering experience, or equivalent technical depth and demonstrated impact.~ Strong hands-on backend development skills and recent experience writing production code.~ Experience leading substantial technical projects across multiple engineers or teams.~ Experience designing transactional systems, external APIs, or integration platforms.~ Strong relational data modeling and system design fundamentals.~ Payments, orders, inventory, reservations, or marketplace systems. Equity.~ Medical, dental, and vision coverage.~