Senior Engineer (.NET & Azure) Contractor - Portugal

We are seeking an experienced Senior .NET and Azure Engineer to join our engineering team on a contract basis. This role is suited to a hands-on engineer who can quickly understand a large, business-critical platform, contribute with minimal ramp-up time, and work effectively across legacy .NET systems, cloud migration initiatives, integrations, test automation, and production support. The successful contractor will be comfortable working in a mature and complex technology environment while helping improve reliability, maintainability, test coverage, performance, and delivery efficiency. Key Responsibilities• Design, develop, test, and maintain applications built with C# and the .NET Framework. • Deliver enhancements and fixes across ASP.NET MVC, Web API, Windows Services, WCF, messaging, database, and integration components. • Support the ongoing migration of systems and workloads to Microsoft Azure. • Contribute to architectural and technical decisions relating to cloud migration, application modernization, observability, scalability, and resilience. • Work with RavenDB, SQL Server, Redis, MSMQ, and custom data replication processes. • Build and maintain integrations with third-party systems, including ERP platforms, SFTP/FTP feeds, email ingestion services, and SOAP APIs. • Support document-processing and OCR workflows using LEADTOOLS and Azure Document Intelligence. • Improve automated test coverage across unit, integration, end-to-end, regression, and performance testing. • Maintain and extend test suites using NUnit, Selenium, SpecFlow, and Playwright. • Diagnose production issues using application logs, telemetry, performance monitoring, and distributed system analysis. • Contribute to Azure DevOps repositories, build pipelines, deployment processes, and internal NuGet packages. • Work closely with developers, testers, product stakeholders, and operational teams to deliver changes safely and efficiently. • Review existing code, identify technical risks, and propose pragmatic improvements. • Use AI-assisted development tools effectively to accelerate analysis, implementation, testing, documentation, and troubleshooting while maintaining engineering quality. • Produce clear technical documentation and communicate progress, risks, and dependencies proactively. • Provision and configure production-like environments in Azure; including compute, networking, and the RavenDB/SQL Server/Redis/MSMQ tiers, to support performance testing, load reproduction, and lift-and-shift piloting.