Senior Engineer (.NET & Azure) Contractor - Portugal

Job Description

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. 

Requirements

Required Skills and Experience

• Strong commercial experience developing applications in C# and .NET Framework.
• Strong experience with Microsoft Azure and cloud migration projects.
• Experience working with ASP.NET MVC 5 and ASP.NET Web API 2.
• Experience developing or supporting Windows Services.
• Strong understanding of enterprise application architecture, distributed systems, and integration patterns.
• Experience with automated testing, including end-to-end or acceptance testing.
• Hands-on experience with NUnit, Selenium, SpecFlow, or Playwright.
• Strong SQL skills and commercial experience with Microsoft SQL Server.
• Experience working with document databases or NoSQL platforms; RavenDB experience is highly desirable.
• Experience with messaging technologies such as MSMQ or equivalent asynchronous messaging platforms.
• Experience diagnosing production defects and performance issues in complex systems.
• Familiarity with CI/CD processes using Azure DevOps, MSBuild, or VSBuild.
• Ability to work effectively with an established codebase containing legacy and modern components.
• Ability to become productive quickly with limited supervision.
• Strong problem-solving, debugging, and analytical skills.
• Clear written and verbal communication.
• A pragmatic, delivery-focused approach with strong attention to quality.

Highly Desirable Experience

• RavenDB 6.x, including:
• Document modelling
• Per-customer database architectures
• Lucene indexing
• Query and index performance optimisation