Senior .NET Engineer – 100% Remote (Spain Only) | UST
Location: Madrid, Spain (Remote)
Company: UST
Job Type: Full-time
Experience Level: Senior
Schedule: Monday to Friday, 9:00 AM to 6:00 PM
Summer Schedule: Intensive working hours (July & August)
Openings: 1
Compensation: Not explicitly mentioned – Competitive salary based on experience
Remote Status: 100% Remote (within Spain only)
Job Summary
Are you a skilled .NET developer passionate about building scalable and resilient microservices? UST, a U.S.-based leader in digital technology solutions and a certified Top Employer, is looking for a Senior .NET Engineer to join its fully remote team in Spain.
In this role, you'll design backend systems using .NET Core 8+ and implement robust DevOps and microservice strategies. This opportunity offers flexible remote work, a stable Monday–Friday schedule, and reduced summer hours in July and August.
Key Responsibilities
Design and implement microservices-based architecture using .NET Core 8 (LTS or later).
Develop RESTful APIs using ASP.NET Core.
Apply resilience patterns using Polly (circuit breakers, retries, bulkheads).
Integrate HttpClientFactory for robust external communications.
Implement native dependency injection and centralized configuration management.
Perform unit testing using xUnit or NUnit.
Use Moq or NSubstitute for mocking dependencies during testing.
Apply SOLID principles and Domain-Driven Design (DDD), including bounded contexts and aggregates.
Implement microservices patterns including API Gateway (YARP or Ocelot).
Collaborate with other developers, architects, and DevOps professionals in an Agile environment.
Required Skills and Qualifications
Minimum 5 years of hands-on experience in backend development using .NET Core.
Strong understanding of REST API development using ASP.NET Core.
Experience with microservices architecture and Domain-Driven Design (DDD).
Proficient in using resilience tools like Polly and HttpClientFactory.
Familiarity with dependency injection and configuration best practices.
Skilled in writing unit tests using xUnit or NUnit.
Knowledge of mocking libraries such as Moq or NSubstitute.
Experience with API gateways like YARP or Ocelot.
Solid understanding of SOLID principles and object-oriented programming.
Strong communication skills and the ability to work in a remote Agile team.
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