Senior Full Stack Developer

This is a client role that is about to open up; we are therefore starting to look for software engineers who would like to join our database so we can reach out to them when we begin working on the position.

About the role

We're looking for a Senior Full Stack Developer to take ownership of a live, multi-repo product suite spanning a customer-facing web app, an internal CRM, and a billing/API platform. This is a senior, high-autonomy position: you'll be trusted to design, build, test, and troubleshoot in production without needing a senior peer looking over your shoulder.

You'll work across the full stack — a .NET 8 / ASP.NET Core backend and a React + Next.js frontend — and you'll be one of the people who raises the engineering bar on testing and CI/CD, which today are enforced standards the team holds itself to rather than a checklist. (Note: role scope and product names below are drafted from the internal role scorecard — double-check company/product details before sharing externally.)

What you'll do

1. Own backend development in C# / .NET 8 and ASP.NET Core: REST APIs, dependency injection, middleware, and authentication — this is the primary backend language across all product repos.
2. Build and maintain frontend features in React, Next.js, and TypeScript across both the customer-facing app and the CRM, working confidently across both rendering models (App Router and client-side state with Redux Toolkit).
3. Design and evolve the data layer: relational database schema, migrations, and query plans, plus Firebase Authentication and Cloud Firestore for identity and real-time data (rules, emulators, service credentials).
4. Establish and grow automated test coverage (xUnit, Jest/Vitest, Playwright) and turn it into an enforced CI gate — current coverage is minimal, so defining the testing strategy is an explicit part of this role.
5. Troubleshoot and resolve issues in production on Azure, including during live incidents.
6. Work on billing and financial/identity integrations (e.g. Stripe, Plaid, Recurly, Persona or similar) as needed.
7. Contribute to real-time and event-driven features using SignalR, GraphQL clients, and idempotent, retry-safe, auditable webhook design.
8. Deliver end to end, autonomously, without requiring senior peer support to unblock your day-to-day work.