Fullstack Developer

We are seeking skilled Full Stack Developers to join our engineering team and build end-to-end features across our React frontend and .NET GraphQL backend. You will work across a modern React monorepo and a robust C# API layer designing responsive UIs, writing GraphQL queries and mutations, implementing business logic, and working with our SQL Server database.This is a high-impact role where your work directly shapes the experience of elite athletes and the professionals who support them. You'll work across a modern, full stack architecture: Frontend Layer Technology Framework React 19 + TypeScript 5.8 (strict mode) Build Vite 5, Node 24+ UI Components Mantine v8, Tailwind CSS Data Visualization Chart.js, Plotly.js, Rechart State Management Zustand, XState (state machines) API Layer GraphQL (urql) with full codegen pipeline Authentication Azure AD / MSAL Routing React Router 7, Generouted (file-based) Testing Vitest, Testing Library, Storybook 8 Rich Content Tiptap editor, FullCalendar Validation Zod Observability Azure Application Insights CI/CD Azure Static Web Apps The frontend is a monorepo hosting multiple apps (Admin, Partner, Public, Report) with shared packages and typed GraphQL codegen. Backend Layer TechnologyLanguage C# 12 / .NET 8 GraphQL HotChocolate v15 (ASP.NET Core) ORM Entity Framework Core 8 (SQL Server) Authentication JWT Bearer + Microsoft Identity Web + custom ApiKey scheme Background Tasks Azure Functions (isolated process, .NET 8) Messaging Azure Service Bus Configuration Azure App Configuration (with refresh/sentinel pattern) Email SendGrid Payments Square Testing xUnit + Snapshooter + Coverlet CI/CD GitHub Actions (CI) + Azure DevOps Pipelines (CD) Integrations The backend integrates with a variety of external services including HubSpot (CRM), Square (payments), SendGrid (email), Slack (notifications), OpenAI (AI features), Microsoft Graph (Azure AD / M365), Azure Blob Storage (file storage), and specialized sports-tech platforms like Hawkin (force plates) and HumanGo (training platform). Responsibilities Build features end-to-end Design and implement complete features from the React UI through to the .NET GraphQL API and SQL Server database, including schema design, mutations, and responsive interfaces. Build data-driven UIs — Develop responsive, performant interfaces for athlete assessment dashboards, performance reports, and scheduling workflows using React 19, TypeScript, and Mantine. Visualize complex data — Create compelling charts, force-time curves, and animated data displays using Chart.js, Plotly, and SVG to communicate physiological metrics to athletes and coaches. Design and extend the GraphQL API — Write HotChocolate queries and mutations in C#, define types and input types, implement DataLoaders to prevent N+1 queries, and maintain efficient data access with Entity Framework Core. Own the GraphQL integration layer — Write typed frontend queries and mutations, maintain the codegen pipeline, and ensure efficient data fetching with urql and Graphcache. Work with the database — Design EF Core models, write migrations, and implement repository patterns against SQL Server. Build background processing — Implement Azure Functions for async tasks such as email delivery, service bus consumers, and third-party integration workflows. Ship with confidence — Write unit and integration tests across both frontend (Vitest, Testing Library) and backend (xUnit), document components in Storybook, and participate in thorough code reviews. Architect for scale — Contribute to monorepo architecture decisions, shared component libraries, API design patterns, and cross-app patterns that support multiple user-facing applications. Stay current — Actively contribute to the evolution of our tech stack, evaluate new tools, and champion best practices in accessibility, performance, security, and developer experience. Qualifications Required 5+ years of professional full stack development experience with React/TypeScript and a server-side language (C#/.NET strongly preferred). Strong understanding of component architecture, hooks, context, and modern React patterns. Experience with GraphQL — both as a consumer (urql, Apollo) and ideally as a backend implementer (HotChocolate, Apollo Server, or similar). Working knowledge of relational databases and ORMs (SQL Server, PostgreSQL, Entity Framework Core, or similar). Familiarity with state management solutions (Zustand, Redux, XState, or similar). Experience with modern build tools (Vite, esbuild, or webpack) and monorepo patterns. Solid understanding of CSS architecture — CSS Modules, Tailwind, or CSS-in-JS. Experience with testing across the stack — unit tests, component tests, integration tests, and snapshot/visual regression. Proficiency with Git, code review workflows, and CI/CD pipelines. Excellent problem-solving skills and ability to collaborate effectively in a distributed team. Nice to Have Experience with C# / .NET 8 and ASP.NET Core. Experience with HotChocolate GraphQL framework. Familiarity with Entity Framework Core migrations and database-first/code-first patterns. Experience with Azure services (Functions, Service Bus, App Configuration, Static Web Apps, MSAL/Entra ID, Application Insights, Blob Storage). Experience with Mantine or other headless/composable UI libraries. Background in sports science, health tech, or data-intensive applications. Experience with Storybook for component-driven development. Familiarity with file-based routing (Generouted, Next.js, or similar). Experience with event-driven architectures and message queues. Benefits Cutting-edge stack — React 19, .NET 8, HotChocolate GraphQL, TypeScript strict mode, full GraphQL codegen — we invest in modern tooling across the entire stack. Meaningful impact — Your code directly helps athletes improve performance and supports physiologists in delivering better care. Growth opportunities — Fast-paced startup environment with room to shape architecture and technical direction across frontend and backend. Collaborative culture — Inclusive team with a focus on personal and professional development. Unique domain access — Work alongside experienced sports coaches and exercise physiologists.