Senior AI Software Engineer (C++ or C#/.NET)

Senior AI Software Engineer (C++ or C#/.NET) - Contract Role

Stelfox is partnering with a Dublin-based software company that is embarking on a significant technology transformation programme. This is a Principal-level engineering role requiring extensive experience modernising complex enterprise software platforms.

Fully Remote (Ireland or UK)

Initial 3-Month Contract | Strong Potential for Extension or Permanent Opportunity

The Opportunity

As senior AI Software Engineer, you will lead the introduction of modern engineering practices that enable Legacy functionality to be migrated safely and efficiently. You will design and implement automated validation mechanisms that allow existing and replacement implementations to be compared with confidence, ensuring that functionality can be modernised without introducing risk.

Alongside the technical work, you will help establish an AI-assisted engineering life cycle, guiding experienced development teams towards new ways of working while maintaining the quality standards expected of a business-critical platform.

Key Responsibilities

• Design and build a parity testing framework capable of validating migrated functionality against existing behaviour.
• Introduce automated testing and regression validation practices across a large Legacy codebase.
• Lead the adoption of AI-assisted software development approaches and engineering workflows.
• Define standards, tooling, governance, and development conventions for agent-assisted engineering.
• Partner with engineering teams to modernise Legacy functionality safely.
• Support the transition towards an API-first architecture.
• Establish measurable engineering practices that improve delivery predictability and throughput.
• Ensure knowledge transfer so internal teams can own and evolve the approach long-term.

Essential Technical Skills

• Strong commercial experience with C++, C# and .NET development
• Experience working within large-scale, enterprise-grade software platforms
• Proven track record maintaining and modernising Legacy applications
• Experience designing and implementing automated testing frameworks, regression testing, and test automation strategies
• Strong understanding of API design, development, and API-first architectures
• Experience working with SQL Server and data-intensive applications
• Software architecture and system design expertise
• Experience using AI-assisted development tools.

If you are interested in this role, click 'apply' to send an updated copy of your CV to Honey Rathore or email (see below) for more details.