[8BE] Senior Fullstack Engineer (.NET + React)

Software Mind Americas

12h

About The Position

Software Mind is partnering with a leading US promotional products and e-commerce company to build a new shipping and delivery service for its white-label B2B commerce platform. The platform runs on Shopify Plus with a .NET microservices backend on AWS. The service will connect major shipping carriers, the storefront, and existing order management systems. This is a short, focused engagement with a discovery phase followed by two-week sprints through production release. The engineer will own the Shopify storefront integration, develop React interfaces, and design and implement .NET 8 Web API endpoints and services. The role includes integrating third-party APIs, working with event-driven messaging, maintaining fast and resilient customer-facing flows, aligning API contracts with the client’s storefront partner, testing and documenting integrations, and participating in reviews, sprint ceremonies, and technical sessions with the client.

Requirements

At least 5 years of full-stack development experience.
Strong C# / .NET skills, including ASP.NET Core and .NET 6 or later.
Strong React and TypeScript skills.
Hands-on Shopify integration experience with Admin API (GraphQL/REST), webhooks, and checkout integration.
Solid REST API design experience with OpenAPI / Swagger.
Experience integrating third-party APIs, including authentication, rate limits, retries, and error handling.
Working knowledge of AWS, including Lambda, SQS/SNS, and ECS.
Knowledge of clean architecture, dependency injection, and DDD/CQRS concepts.
Testing discipline across backend and frontend.
Experience with Docker and CI/CD.
Excellent written and spoken English for daily client interaction.

Nice To Haves

Shipping or carrier API experience.
Shopify Plus, Hydrogen, or headless commerce storefront experience.
Experience building admin UIs with component libraries such as Polaris, MUI, or similar.
Retail, e-commerce, or promotional products domain knowledge.

Responsibilities

Build and own the Shopify storefront integration, including Admin API, webhooks, and checkout integration points.
Develop React interfaces, including admin and configuration tools.
Design and implement .NET 8 Web API endpoints and services.
Integrate third-party APIs behind clean adapter layers.
Work with event-driven messaging (SNS/SQS), including idempotent handling and retries.
Keep customer-facing flows fast and resilient.
Align API contracts with the client’s storefront partner.
Write unit, integration, and component tests.
Document APIs using OpenAPI and document integration flows in Confluence.
Take part in code reviews, sprint ceremonies, and technical sessions with the client.