Hi, I'm Spencer, building Cairn, a calm record of regulated work, in London

I'm a hands-on software engineer and architect with nearly thirty years' experience building financial-services platforms. I co-founded Wealth Dynamix and Portemis, and most recently owned platform architecture at Wealth Dynamix across Azure infrastructure, deployment, reliability and observability. Since July 2026 I've been building Cairn, a SaaS platform, end-to-end in .NET, React and PostgreSQL.

I also build tools for understanding and evaluating LLM systems in C# and Python, including tool-calling agents, multi-agent experiments and MCP tooling. My open-source project Vessel records LLM traffic for inspection, replay and scoring. I publish experiments on model behaviour, context handling, observability and inference performance.