[8BE] Senior Backend Engineer (.NET)
Software Mind - San José, San José Province, cr, Remote
Still listed by Software Mind · checked today · posted 22 Oct 2026 (yesterday)
Skills: C#, .net, Asp.net core, Rest apis, Openapi, Swagger, Cqrs, DDD, Clean architecture, AWS, Lambda, SQS, S3, RDS, Dynamodb, Postgresql, Sql server, Mongodb, JWT, Oauth 2.0, Docker, Xunit, Reqnroll, Fluenthassertions, Eventbridge, Shopify, Amazon sp-api, Walmart marketplace api, Jira
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
- 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)
- Event-driven architecture (EventBridge, RabbitMQ)
- Keycloak and multi-realm identity management
- EF Core with Npgsql
- Promotional products or print-on-demand domain knowledge