Senior .NET Engineer

Quick Facts

• Remote work from Poland with occasional business travel
• English working language

Description

Senior .NET engineer role focused on stabilising and modernising an existing .NET application. You will reduce technical debt, improve engineering practices, and strengthen quality and operational reliability for long-term dependable operations.

Responsibilities

• Build a strong understanding of the existing codebase, architecture, integrations, and business-critical workflows
• Create and drive a risk-based technical debt roadmap for stability, security, maintainability, and supportability
• Modernise the .NET application and key dependencies incrementally while protecting business continuity
• Diagnose and resolve production issues, recurring defects, performance bottlenecks, and integration failures
• Improve automated testing, code quality, logging, monitoring, and operational documentation
• Strengthen CI/CD, deployment practices, environment consistency, and safe rollback approaches
• Document design decisions, interfaces, runbooks, and critical business logic; share knowledge across the team
• Prioritise improvements with business and technical stakeholders based on operational risk and business value

Requirements

• Educational background in Computer Science, Software Development, or Engineering
• Strong hands-on experience developing and maintaining backend applications with C# and .NET / ASP.NET Core
• Experience modernising legacy or business-critical applications without disrupting ongoing operations
• Solid knowledge of relational databases, SQL, and Entity Framework
• Experience designing, maintaining, and troubleshooting enterprise integrations and APIs
• Practical experience with Microsoft Azure, including application hosting, monitoring, and cloud operations
• Experience with unit, integration, and regression testing and improving test coverage in existing systems
• Good understanding of secure coding, dependency management, and software lifecycle risks
• Experience with CI/CD, source control, and modern software quality practices
• Strong analytical and problem-solving skills to turn findings into pragmatic improvement plans
• Ability to work independently with high ownership and accountability
• Excellent communication skills with technical and business stakeholders

Nice to have

• Vue.js or another modern JavaScript framework
• Azure App Service, Azure SQL, and Infrastructure as Code (Bicep, ARM templates)
• Observability, structured logging, alerting, and production support
• Financial, invoicing, or payment workflows
• SAP or other ERP integrations
• Experience in clinical development, life sciences, or another regulated enterprise environment