C# Developer

GCS Recruitment; Saint Petersburg (FL); On-site; USD 80,000 - 100,000; Full time

Job summary

GCS Recruitment is seeking skilled .NET Engineers in Saint Petersburg, Florida, to join their team. The role focuses on migrating existing VB6 and VB.NET applications to a modern .NET C# WPF environment, utilizing AI-powered tools to improve efficiency.

Ideal candidates will have strong hands-on experience with the .NET ecosystem and a proven track record working with legacy systems. Join a dynamic environment where your contributions will directly impact the modernization of critical systems.

Qualifications

• Strong hands-on experience with C# and the .NET ecosystem.
• Proven experience working with legacy systems (e.g., VB6, VB.NET).
• Familiarity with WPF application development.

Responsibilities

• Lead the migration of legacy VB6 and VB.NET applications to .NET C# WPF.
• Use AI-powered development tools to enhance speed, efficiency, and code quality.
• Design and implement robust test harnesses to ensure correctness and stability.

Skills

C# and .NET ecosystem

VB6 and VB.NET experience

WPF application development

AI-assisted development tools

Code refactoring and modernization

Ability to work under tight timelines

Tools

Codex

Claude Code

Cursor

Job description

We are seeking skilled .NET Engineers to join our team and play a critical role in modernizing legacy systems. The primary focus of this role is migrating existing VB6 and VB.NET applications to a modern .NET C# WPF environment within an accelerated delivery timeline.

Key Responsibilities

• Lead the migration of legacy VB6 and VB.NET applications to .NET C# WPF
• Use AI-powered development tools to enhance speed, efficiency, and code quality
• Contribute to an aggressive delivery roadmap targeting
• Design and implement robust test harnesses to ensure correctness and stability
• Establish safety protocols to safeguard data integrity during migration
• Perform automated refactoring and support framework migration initiatives
• Troubleshoot complex legacy systems and resolve architectural challenges

Required Skills & Experience

• Strong hands‑on experience with C# and the .NET ecosystem
• Proven experience working with legacy systems (e.g., VB6, VB.NET)
• Familiarity with WPF application development
• Experience using AI‑assisted development tools such as Codex, Claude Code, Cursor or other similar tools
• Solid understanding of code refactoring, modernization, and migration strategies
• Ability to work under tight timelines and deliver high-quality results