eCommerce SaaS platform development

We're looking for a solid, self-directed developer to take over part-time development of internal SaaS platform built for e-commerce businesses to manage their entire financial operations in one place. The product includes: order management, invoice generation, expense tracking, P&L reporting, multi-store management, audit logging, user management, etc. The codebase is clean and well-structured. You're building on top of something solid, not cleaning up a mess. Tech stack you must know: Backend C# / .NET 10 — Clean Architecture + CQRS (MediatR), non-negotiable PostgreSQL + Entity Framework Core ASP.NET Core — REST APIs, auth, background services Docker / docker-compose Frontend React 19 + TypeScript Vite, Tailwind CSS v4, shadcn/ui React Router v7 Integrations Shopify API — GraphQL specifically (strong experience required) Comfortable working with multiple third-party API integrations (accounting software, currency services, etc.) — ability to read docs and integrate new services independently Workflow & tooling Git — clean commits, branching, PR discipline GitHub — code review, issues, project tracking GitHub Actions / Workflows — CI/CD pipelines, automated builds and deploys What the work looks like: Finishing features mid-development Adding new integrations and modules Maintaining CI/CD and deployment pipelines Shipping incrementally with code quality intact You are NOT a fit if: You rely on AI to write code you can't read or explain You need heavy hand-holding on architecture decisions You've never worked in a structured backend (Clean Architecture, CQRS, layered projects) You treat Git as a "save button"