Senior .NET Developer

Overview

For our client, we are seeking an experienced Senior .NET Developer with proven hands-on experience in migrating production applications from .NET Framework to .NET 8, including practical Gen AI tools experience (including advanced usage of coding agents).

The ideal candidate has extensive professional experience in C# and .NET, with a strong background in designing, developing, and maintaining .NET applications, particularly in API development and application modernization.

• Lead or contribute to migration projects moving applications from .NET Framework to .NET Core/.NET 8+, ensuring safe, incremental PRs and minimal risk.
• Design, develop, and maintain .NET applications, with emphasis on API development and modernization.
• Collaborate with teams on integrating AI-driven solutions and using Gen AI tools (including advanced usage of coding agents).
• Familiarity with CI/CD pipelines (Azure Dev Ops, Git Hub Actions, etc.) and deployment of ASP.NET applications to IIS and/or cloud platforms.
• Manage certificates, secrets, and environment configuration; implement secure Dev Ops practices.
• Contribute to automated test suites and quality gates.

• Overall 7+ years of professional experience in C# and .NET.
• Practical experience with advanced usage of coding agents.
• Hands-on experience with:
  • .NET Framework (4.x)
  • Copilot agents, Claude Code or another Gen AI solution
  • ASP.NET Core (.NET 6 / 7 / 8 / 10)
  • Dapper or other ORM frameworks
  • Redis
  • NLog or modern logging frameworks
  • Swagger / OpenAPI, JSON serialization and model binding
  • API development and versioning strategies
• Familiarity with CI/CD pipelines (covered above) and experience deploying ASP.NET applications to IIS and/or cloud platforms.
• Working knowledge of certificates, secrets, and environment configuration.
• Comfortable working with automated test suites and quality gates.
• Experience in integrating AI-driven solutions.
• Migration-Specific
  
  Experience:
  
  demonstrated experience migrating applications from .NET Framework to .NET Core / .NET 8.
• Strong understanding of dependency injection patterns across Framework and Core, middleware and request pipeline differences, and ability to decompose migration work into small, safe PRs.
• Must possess a legal work permit in Poland.

• Attractively located office with collaboration spaces
• Onsite parking space for employees
• Referral program with financial bonus
• Life Insurance
• Budget for development (including language courses and others), clear career path with the possibility to gain experience in international environment
• Access to internal Learning Platform with multiple trainings oriented for professional growth
• Access to MyBenefit platform (Multisport included)
• Team Building activities
• Charity initiatives
• Working environment promoting diversity and inclusion