Setup: Freelance (Daily Rate / Limited Company / Umbrella / Sole Trader)
Location: Barcelona, Spain (hybrid)
We are looking for a hands-on Software Developer to support the modernisation of a business-critical legacy platform into a scalable, API-first architecture using React and .NET Core technologies.
Key Responsibilities
- Build and enhance ASP.NET Core Web APIs.
- Develop modern React SPA components and integrate them with backend services.
- Support the migration of legacy Web Forms functionality into reusable API-driven solutions.
- Work with SQL Server, business logic layers, validation and error handling.
- Contribute to testing, debugging and overall application quality.
- Support CI/CD processes and collaborate closely with architects and development teams in an Agile environment.
Must-Have Skills
- 3+ years of software development experience.
- Strong C# and ASP.NET Core Web API expertise.
- Strong React and JavaScript development experience.
- Experience with REST APIs and SQL databases.
- Strong communication skills and ability to work independently.
- Fluent English and Spanish.
Nice-to-Have
- Experience with Web Forms or other legacy systems.
- AWS exposure (S3, API Gateway, Lambda).
- JWT/OIDC authentication experience.
- CI/CD knowledge.