Fullstack Engineer

Note: No recruiters pleaseNote: Applicants must have permanent work authorization in the US; we are not sponsoring visas for this roleNote: This is an in-office position, we are default ‘in office' and if you are not in the Raleigh, NC/Triangle area, you must relocate at your own expense, we do not have a relocation package/budget for this role.About the roleJoin us to build an AI-native, Agentic e-commerce platform. You'll ship end-to-end features across a Next.js/TypeScript frontend and C#/.NET back end, powering an Agentic, event-driven, multi-tenant SaaS platform. Expect rapid iteration, strong ownership, and real customer impact.Our stack Frontend: Next.js, React, TypeScript, Tailwind/shadcn, SSR/ISR, client/server componentsBackend: C#/.NET 9, microservices, minimal APIs, DI, background workersData: PostgreSQL, Redis; Neo4jEvent-driven Dapr architecture with pub/subAI-native: Latest agentic components like AutoGen, Semantic Kernel, vector platform using latest Semantic Kernel LLMs, vector DBs, function/tool callingCloud/Platform: Azure, AWS, Supabase, Fly.io, DockerObservability: OpenTelemetry, tracing/metrics/logging, dashboards What you'll do Build product experiences in Next.js + TypeScript with polished UXDesign resilient .NET services and event-driven workflows (idempotency, retries, DLQs)Integrate and evaluate LLMs/agents: retrieval, tools, and guardrailsOwn features end-to-end: schema/design, API contracts, tests, telemetry, rollout and learningsContribute to platform/devex: CI/CD, preview envs, codegen/AI coding tools, internal libraries Minimum qualifications 3+ years with modern TypeScript/React or C#/.NET shipping production appsSolid grasp of SSR, state management, API design, and relational data modelingExperience with containers and cloud deploymentVersion control and code review hygiene (Git), automated testing fundamentals Nice to have Next.js App Router, React Server Components, Tailwind/shadcn.NET 9, minimal APIs, background jobs, Clean Architecture, CQRSEvent-driven messaging (Dapr)Vector databases, RAG, LLM tool use/agents, prompt/response evaluationE-commerce: catalogs, marketplaces (Amazon/Walmart/eBay), feeds How we work Builder culture: fast iterations, small PRs, daily deploys, trunk-based developmentIn-office collaboration for speed and quality; fewer meetings, more co-creation What you'll learn Agentic patterns in production (tool orchestration, planning, safety/guardrails)Real-time features with WebSockets/streams and backpressureMulti-tenant SaaS design (isolation, quotas, metering, cost/perf tuning)E-commerce AI: surfacing insights and actions that move revenue BenefitsWhile we're a seed-stage startup, ReFiBuy offers: Health, Dental, Vision - 80% of base plan covered by ReFiBuy401k w/ match: 100% of contribution up to 1% of salary and 50% up to 5%, no vestingIncentive Stock Options (ISOs) - As an early stage startup, you get in on the ground floor, 4yr quarterly vesting.Parking is covered by ReFiBuyOffice: We work out of the Raleigh Founded office at 509 W. North St, Raleigh, NC 27603 which offers a Glenwood South location, where you can easily walk to restaurants and amenities. The facility offers a spacious breakroom, hang out areas, Wellness room and more. About ReFiBuy (refibuy.ai)Founded by four experienced ecommerce operators (ChannelAdvisor, Rithum, MikMak, Walmart), ReFiBuy is one of the most experienced AI startups in the Triangle. We are AI Native, meaning everything we do starts and ends with an AI foundation. Compared to traditional companies you will feel like you are going 100x faster. Compared to a traditional startup, 10-20x faster. If you like to build great and fast, be innovative, go home exhausted from learning so much, and work on projects where you make an immediate impact, ReFiBuy is perfect for you!

Created: 2026-03-04