Fullstack Engineer, App Platform

🚀 Join the Future of Commerce with Whatnot! Whatnot is the largest live shopping platform in North America and Europe to buy, sell, and discover the things you love. Whether it's trading cards, fashion, electronics, or live plants, our sellers are building real businesses across hundreds of categories. We're building live commerce at a scale that's never been done in the West, and there's no playbook to copy. The people here are shaping how an entirely new industry develops. As a remote co-located team, we're inspired by our values and anchored in hubs across the US, UK, Ireland, Poland, Germany, and Australia. We move fast, stay close to our users, and focus on the work that drives the most impact. We're one of the fastest growing marketplaces and were recently named the #1 Best Startup Employer in America by Forbes. Check out the latest Whatnot updates on our news and engineering blogs and join us as we enable anyone to turn their passion into a business and bring people together through commerce. 💻 Role App Platform is Whatnot's client infrastructure team, building the consistent, reliable foundation that every product team builds on top of across iOS, Android, and Web. Rather than owning a single feature surface, the team pushes technical boundaries so product pods can move fast without sacrificing quality — owning things like app stability and observability, the Whatnot Design System, localization, core components, and the shared architecture that keeps our apps performant and consistent at scale. As an Fullstack Engineer on App Platform, you'll focus on the infrastructure and building blocks that feature teams rely on: scaling our Web backend services, strengthening our networking and persistence layers, improving our client testing harnesses, driving app stability and crash reduction, and partnering closely with product teams to make sure the "right way" to build is also the easiest way. It's a high-leverage role for someone who wants their work to compound across the entire app rather than a single feature. We offer flexibility to work from home or from one of our global office hubs, and we value in-person time for planning, problem-solving, and connection. Team members in this role must live within commuting distance of our New York, Seattle, San Francisco or Los Angeles hub. This is a strong fit for an engineer who enjoys shipping product-facing platform work, cares deeply about user trust and message quality, and is excited by the challenge of building systems used by many teams across the company. We offer flexibility to work from home or from one of our global office hubs, and we value in-person time for planning, problem-solving, and connection. Team members in this role must live within commuting distance of our New York or Seattle hub. 👋 You People who do well at Whatnot tend to be comfortable figuring things out as they go, biased toward action, and genuinely curious about what they're building. They care more about outcomes than credit and stay close to the product and the people using it. As our next Fullstack Engineer you should have 5+ years of software development plus: Bachelor’s degree in Computer Science, a related field, or equivalent work experience. Web development experience with React, using GraphQL for API development, and modern frontend applications (exposure to Next.js framework is not required but preferred). Backend expertise: Proven track record of building end-to-end high-scale product experiences as a fullstack engineer. Experience with Node or Python on backend, and/or Postgres databases is a plus. Excellent product instincts—you first think about users rather than the best technical solution. Care deeply about the craft of software engineering, maintaining systems at scale, and how to balance the productivity and velocity of teams while maintaining a high quality end-user experience. You can mentor others, and prioritize building inclusive, supportive teams. Contribute