Artificial Intelligence Engineer

Agentic AI Engineer (.NET) — Contract * Client: Global Technology Leader – NASDAQ Listed * Location: Hybrid — Bristol - 3 Days Per Week * Duration: 6 months + Intention to extend (Greenfield Multi-Year Programme) * Day rate: £500 — Inside IR35 * Start date: ASAP Our client, a global leader in software systems, is building AI agents that generate production .NET code under developer supervision. The goal of this greenfield is a spec-driven pipeline where a specification and technical plan drive what the agent builds, and a developer reviews and validates the output at every stage before it ships. We are looking for a contractor who has built and shipped AI agents in production and who brings a strong .NET background. This is a hands-on engineering role with scope to set the technical direction and bring the wider team up to speed on the approach. What you will do: * Design and build agents that produce production-grade .NET code. * Implement a spec-driven development workflow (spec, plan, tasks, implement), using Spec Kit. * Build review and approval gates so developers can verify and correct agent output before it is merged. * Integrate tools and data sources into the agents via MCP (Model Context Protocol). * Set up evaluation, guardrails and tests to catch incorrect output early. * Work alongside engineering team’s and upskill them on agentic patterns and the spec-driven approach. Essential experience: * Proven track record building and shipping AI agents in production, including tool calling, orchestration and multi-step workflows. Prototype-only experience will not be enough. * Strong .NET and C# background (.NET 8/9, ASP.NET Core). * Hands-on with a .NET-native agent framework, such as Microsoft Agent Framework or Semantic Kernel. * Experience building agents whose output is code, with a clear focus on validating and verifying correctness. * Familiarity with spec-driven development, ideally Spec Kit. * Experience integrating tools via MCP. * Designing human-in-the-loop review and approval gates within agent workflows.