Senior Full Stack EngineerFlexAI is looking for a Senior Full Stack Engineer who can build end-to-end features across our PaaS platform — including frontend UI layers, backend APIs, data models, and integrations with compute and infrastructure systems. You will work on developer modules Admin modules, Marketplace, and Licensing, shaping the user experience and backend logic.This position is In-Person and located at our San Jose, CA Office.What You'll DoBuild and ship end-to-end features across our platform (developer tools, marketplace, billing, admin)Develop high-performance UIs using ReactDesign and implement APIs and backend services using Python (FastAPI) and/or Node.jsDefine clean, scalable contracts between frontend and backendWork on data-intensive workflows (jobs, compute orchestration, resource management)Collaborate with platform and infrastructure teams to build reliable systemsDebug and optimize across the stack — from UI to backend performanceOwn features end-to-end : design, build, ship, and operateWhat You'll Need to Be Successful5+ years of experience with a Bachelor's and/or Master's degree building Full Stack applicationsStrong skills in:Frontend: React (modern stack)Backend: Python (FastAPI or similar) or Node.jsExperience designing and working with APIsComfortable with data models, async workflows, and scalable systemsAbility to operate independently and move fast with high ownershipStrong communication and collaboration skillsExperience working in startup environmentsComfortable leveraging AI coding tools and agents to move fasterNice to HaveExperience with cloud platforms, developer tools, or compute systemsFamiliarity with Kubernetes, CI/CD, and observabilityExposure to billing, licensing, or marketplace systemsWhat We OfferA competitive salary and benefits packageWork on cutting-edge AI infrastructureBuild products used by developers and enterprisesHigh ownership, fast execution, real impactCollaborative, high-caliber team