Senior Software .NET Engineer

Nexi is Europe's PayTech company operating in high-growth European markets and technologically advanced countries. It is listed on Borsa Italiana's MTA and offers innovative products across Merchant Services & Solutions, Cards & Digital Payments, and Digital Banking & Corporate Solutions. Nexi focuses on meeting customer needs and creating business opportunities through digital payment technology and innovation.

• University degree in computer science or comparable field
• 6+ years of commercial software development experience
• Extensive experience with C# and .NET across generations: .NET Framework 4.x (ASP.NET WebForms/MVC) and modern .NET 6/8 with ASP.NET Core
• Hands-on experience with modernizing or migrating legacy applications using re-platforming, incremental refactoring, or strangler-fig-style approaches
• Strong knowledge of software design principles and patterns, including SOLID and clean architecture
• Solid experience with Microsoft SQL Server and data-layer refactoring
• Practical experience with AI-assisted development tools (e.g., GitHub Copilot or similar LLM-based tooling)
• Experience with automated unit and integration testing
• Fluency in Polish and very good communication in English
• Availability to work in hybrid mode with monthly office visits for remote workers

• Analyze legacy codebase and plan incremental, low-risk migration path module by module
• Design and implement migration of application components from .NET Framework 4.x / ASP.NET (WebForms, MVC) to .NET 8 / ASP.NET Core
• Refactor code towards SOLID principles and clean architecture as part of migration
• Modernize the Microsoft SQL Server data layer and platform's system integrations
• Use AI-assisted development tools (e.g., GitHub Copilot, LLM-based tooling) for legacy code analysis, refactoring, and test generation
• Build automated test coverage including unit and integration tests for migration verification
• Collaborate with development teams and stakeholders on scope, sequencing, and technical decisions
• Mentor less experienced developers and share modernization knowledge within the team

Availability to work in a hybrid mode; remote workers are invited to the office once every month.