Senior Software Engineer: AI-Driven Legacy Modernisation

RedRock Resourcing; Reading; On-site; GBP 70,000 - 110,000; Full time

Job summary

RedRock Resourcing is hiring for a role that isn't a traditional software engineer position. You will work at the intersection of software engineering, architecture, AI, developer experience and legacy modernisation, shaping the systems and guardrails that let engineers ship better software safely.

The ideal candidate has a strong software engineering foundation, deep C#/.NET experience with large or legacy systems, and familiarity with AI coding agents and modern tooling to accelerate

Qualifications

• Serious software engineering foundation.
• Deep experience in C#/.NET with legacy systems.

Responsibilities

• Use AI coding agents to refactor and modernise legacy codebases.
• Design the engineering harness for AI agents to have context, rules and constraints.
• Build repository-level instructions, agent skills, prompts and dynamic context.
• Work with technologies such as Claude Code, MCP and other agentic development tools.
• Establish automated testing and AI evaluation frameworks to balance speed and quality.
• Build guardrails, sandboxes and CI/CD controls around AI-driven development.

Skills

Strong software engineering foundation

C#/.NET experience

AI integration experience

Tools

Claude Code

Cursor

GitHub Copilot

Codex

Job description

RedRock Resourcing is hiring for a role that isn't a traditional software engineer position. You will work at the intersection of software engineering, architecture, AI, developer experience and legacy modernisation, shaping the systems and guardrails that let engineers ship better software safely.

The ideal candidate has a strong software engineering foundation, deep C#/.NET experience with large or legacy systems, and familiarity with AI coding agents and modern tooling to accelerate