Senior Software Engineer, Product

Senior Software EngineerArena is the platform for evaluating how AI models perform in the real world. Founded by researchers from UC Berkeley's SkyLab, we're on a mission to measure and advance the frontier of AI for real-world use, and to build the foundation for everyone to understand, shape, and benefit from it.Tens of millions of people use Arena each month to evaluate how frontier systems handle the work they actually do. The preferences they share power the most transparent, rigorous, and human-centered evaluations in AI. Leading AI labs, enterprises, and independent researchers rely on our work and open datasets to understand how models behave in real workflows: agentic coding, creative generation, professional productivity, and beyond. We go beyond leaderboards and decompose what human experience reveals about AI, so models advance toward the work people actually do.We're a team of researchers, academics, builders, and creatives from UC Berkeley, Google, Stanford, and DeepMind. We seek truth, move fast, and value craftsmanship, curiosity, and impact over hierarchy. We're building a company where thoughtful, curious people from all backgrounds can do their best work together, in an office culture that radiates excellence, energy, and focus.About the RoleWe're looking for a Senior Software Engineer to own features end-to-end across Arena's platform — from understanding the problem, through designing and building the solution, to shipping it, measuring its impact, and iterating. This is a hands-on IC role for someone who writes code every day, cares deeply about what happens after launch, and is excited to shape how people interact with cutting-edge AI.You'llOwn features from technical scoping through deployment and post-launch iteration — not just build them, but make sure they workDesign and extend schemas, APIs, and business logic to support new product capabilitiesShip high-quality product code across the stackIncorporate real user feedback — from data, direct user contact, or your own product instincts — to improve what you've shippedWork closely with ML researchers to turn research services to production, making them consumable for product developmentCollaborate across design, product, and engineering to figure out what to build, not just howIdentify and advocate for improvements to development, testing, and deployment practicesYou'll Have4+ years of experience in software engineering, with a focus on product developmentExperience building user-facing web applications spanning frontend, backend/API, and database — in any stack. You understand the request lifecycle across layersClear, concise communication — you explain technical decisions well, distinguish your work from the team's, and proactively share contextEvidence of shipping and iterating — you can describe the full arc of a feature you owned: problem, solution, code, what happened after launch, and what you'd change nowA product engineering identity — you care about whether the thing you built actually worked for users, not just whether the code was cleanGenuine curiosity about AI evaluation and Arena's mission — you've looked at the product and can articulate why this domain matters to youBonus PointsFamiliarity with our stack: NextJS, React, TypeScript, Tailwind, ShadCN, HonoJS, Postgres, VitestExperience with Supabase or Vercel's AI SDKYou've shipped without PM or design support — determined what to build by talking to users or looking at dataOur Tech Stack:NextJSReact + TypeScriptTailwind + ShadCNHonoJSPostgresVitestWhat We OfferWe offer competitive compensation and equity aligned to the markets where our team members are based. The base salary range will depend on the candidate's permanent work location.Comprehensive health and wellness benefits, including medical, dental, vision, and additional support programs.The opportunity to work on cutting-edge AI with a small, mission-driven teamA culture that values transparency, trust, and community impactCome help build the space where anyone can explore and help shape the future of AI.Arena Intelligence provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability, genetics, sexual orientation, gender identity, or gender expression. We are committed to a diverse and inclusive workforce and welcome people from all backgrounds, experiences, perspectives, and abilities.