About the role You will build features end to end: the API service on the backend, the Next.js application on the frontend, and the design decisions that connect them. This is a hands-on role with real ownership. You will help decide how things are built, not just implement someone else's plan. What you will do • Build and maintain Python services (FastAPI) that are fast on reads and correct on writes. • Design the data model and write the SQL behind it. • Build product screens in Next.js and React that hold up with real data: dense tables, dashboards, forms with complex state. • Decide what renders on the server and what renders on the client. • Add logging, metrics, and tracing so problems can be diagnosed in production. • Write a short design doc before building anything that crosses a service boundary. • Review other people's code carefully. What we are looking for Python backend • 5+ years writing production Python, including a modern async framework such as FastAPI. • Comfortable with async/await, background tasks, and structured error handling. • You write tests as part of building, not after. SQL • Solid relational modelling and comfort writing non-trivial queries by hand. • You can read a query plan and explain why something is slow. • You have run schema migrations on a live system. Frontend • 3+ years of production React, with a real understanding of why a component re-renders. • Next.js App Router in production: server components, route handlers, caching. • TypeScript used to model the domain, not just to satisfy the compiler. • A clear view of what belongs in server state, client state, and the URL. Architecture and system design • You can turn an ambiguous requirement into a design with stated assumptions and trade-offs. • Comfortable with the fundamentals: idempotency, retries, timeouts, caching and invalidation, consistency. • You have made a wrong call, caught it, and fixed it. We will ask about this. Nice to have • Experience with an analytical database such as Snowflake or BigQuery. • Event-driven or queue-based systems in production. • Authorization design: row-level access, tenant isolation.