Principal AI Engineer

Principal AI Engineer – AI / .NET Core / React Remote-first | UK | Permanent Change Digital are exclusively supporting this exciting opportunity to recruit a Principal AI Engineers for a global technology organisation developing market-leading enterprise software across Legal, Risk, Compliance and HR. This is a senior, hands-on technical leadership role where you will shape the AI technical direction, design and deliver production-grade AI capabilities, and help drive the adoption of AI across the software development lifecycle. The Role: As Principal AI Engineer, you will: • Own the architecture and technical direction for AI capabilities, including LLMs, agents, RAG, model management and evaluation. • Design and deliver AI-powered enterprise features from prototype through to production. • Remain hands-on with .NET Core (C#) and React (TypeScript) development. • Drive the adoption of AI across the SDLC, including coding assistants, agentic development, testing and code review. • Build trustworthy AI through evaluation frameworks, guardrails, observability and governance. • Lead technical and architectural discussions across engineering, product, security and architecture teams. • Mentor and develop senior engineers through design reviews, code reviews, pairing and knowledge sharing. • Enhance CI/CD and AI Ops capabilities, including model/prompt versioning, automated evaluation and monitoring. • Help shape the long-term AI roadmap and make pragmatic build-versus-buy decisions. What We're Looking For: • Professional software development experience, including Principal, Lead or Staff-level responsibility. • Strong hands-on experience with .NET Core / C# and React / TypeScript. • Proven experience designing and delivering production AI solutions. • Strong knowledge of LLMs, prompt engineering, RAG, MCP and agentic/tool-calling systems. • Experience with Azure OpenAI / Azure AI Foundry or equivalent cloud AI platforms. • Experience with AI orchestration frameworks such as Semantic Kernel. • Strong REST API development experience. • Experience with Entity Framework and Azure SQL / SQL Server. • Understanding of AI evaluation, benchmarking and improving AI system quality. • Strong awareness of AI security, including prompt injection, data privacy and secure handling of sensitive information. • Experience with Git, CI/CD and Azure DevOps or similar platforms. • Strong technical leadership, mentoring and architecture experience. Desirable Experience: Experience with areas such as: • SLMs, fine-tuning, CAG and vector databases. • AI observability and multi-agent systems. • AI/ML and LLMOps pipelines. • Docker, Linux and distributed caching such as Redis. • OAuth, SSO and enterprise authentication. • Infrastructure-as-code and automation. • Enterprise SaaS or regulated environments such as LegalTech or FinTech. • Applying AI to document, contract or natural-language workloads. Why This Opportunity? This is an excellent opportunity for a senior AI engineer/architect who wants to have genuine influence over how AI is designed, built and adopted at enterprise scale. You will have the opportunity to shape AI strategy from architecture through to production, while remaining hands-on with modern AI technologies and software engineering. If you are an experienced Principal AI Engineer, Staff Engineer, AI Architect or Senior AI Technical Lead with strong .NET and modern AI experience, I would be very interested in speaking with you. Please get in touch with your CV for a confidential discussion. Mitesh Fatnani – mitesh.fatnani@change-digital.co.uk