We’re building the backend of a white-label B2B e-commerce platform for a leading US promotional products company. The platform powers multiple branded Shopify Plus storefronts. It runs on a fully decoupled microservices architecture on AWS covering Identity, Profile, Order Management, Inventory, Pricing, Catalog, and Marketplace integrations. The existing legacy services stay supported while the migration happens.
What you’ll do:
- Design and build scalable RESTful microservices with ASP.NET Core Web API (.NET 8) and CQRS
- Own core services: Order Management, Inventory, Pricing Engine, Catalog Sync, and Notifications
- Build and consume Shopify Webhooks and REST/GraphQL APIs (Storefront API, Admin API)
- Integrate with external systems such as Amazon SP-API, Walmart Marketplace API, ERP, payment gateways, and tax services
- Work with legacy services where the migration is phased or partial
- Write unit, integration, and BDD tests (xUnit, Reqnroll, FluentAssertions)
- Define API contracts and inter-service communication (SQS, EventBridge) with the Team Lead
- Take part in code reviews and architecture decisions, and help hold the engineering standard
- Support environment setup and infrastructure-as-code with DevOps on AWS
- Join sprint planning, stand-ups, and technical discussions with the client
Must have:
- 4+ years of backend development with strong C# / .NET (ASP.NET Core, .NET 6+)
- Solid grasp of clean architecture: DDD, CQRS, repository pattern, dependency injection
- Experience building and integrating REST APIs, including OpenAPI / Swagger
- Working knowledge of AWS: Lambda, SQS, S3, RDS or DynamoDB
- Relational (PostgreSQL or SQL Server) and NoSQL (MongoDB) databases
- JWT / OAuth 2.0 authentication
- Brownfield experience: plugging new services into existing systems
- Docker and containerized workflows
- Strong written and spoken English
- Agile/Scrum with Jira
Nice to have:
- Retail, e-commerce, or B2B commerce experience (catalogs, pricing engines, cart/checkout, marketplace integrations)
- Marketplace API integrations (Amazon SP-API, Walmart)
- Event-driven architecture (EventBridge, RabbitMQ)
- Keycloak and multi-realm identity management
- EF Core with Npgsql
- Promotional products or print-on-demand domain knowledge