Senior .NET Developer (Legacy Specialist & AI Expert)

Location: Pécs, Budapest, Debrecen, or Szeged, Hungary. Remote work is available only within Hungary due to European taxation regulations.

Company

hirify.global is a Deutsche Telekom Group subsidiary providing IT and telecommunications services to large corporate customers across Germany and other European countries.

What you will do

• Design and implement complex features within an existing .NET ecosystem.
• Reverse-engineer undocumented and monolithic legacy code to identify business rules and technical flows.
• Use AI coding assistants and development environments such as Cursor, Windsurf, Claude Code, and VS Code extensions for code comprehension, documentation, and refactoring.
• Write unit and integration tests to protect legacy modules during modernization.
• Investigate complex bugs and performance bottlenecks as a high-level escalation point.
• Build lightweight administrative and maintenance utilities with Microsoft PowerApps.

Requirements

• 6+ years of professional software development experience.
• Deep expertise in .NET and C#, including older .NET Framework versions and monolithic architectures.
• Hands-on familiarity with AI coding assistants, prompt engineering, or local model experimentation.
• Strong knowledge of SOLID principles, design patterns, advanced debugging, and profiling.
• Commitment to TDD and automated unit and integration testing.
• Must work remotely from within Hungary.

Culture & Benefits

• Work in a highly autonomous, lean engineering unit.
• Combine legacy stability with modern cloud-native and AI-augmented engineering.
• Follow disciplined, evidence-based SDLC practices.
• Use risk-mitigated "Strangler Fig" modernization patterns to evolve legacy systems.
• Contribute to internal tools used across a large Deutsche Telekom IT organization.