# Field notes

> Technical write-ups on health tech, AI search, and software engineering.

## [Serving Markdown to Bots with Content Negotiation](https://troll-tech.co.uk/notes/markdown-content-negotiation.md)

*2 June 2026 · 7 min read*

How a small Express middleware can hand AI crawlers a cheap Markdown representation of each page instead of a full SSR render, cutting server load and letting you raise crawler rate limits instead of throttling them.

## [GEO vs SEO: Where the Boundary Actually Is](https://troll-tech.co.uk/notes/geo-vs-seo.md)

*1 June 2026 · 5 min read*

A rigorous look at which Generative Engine Optimization mechanisms are genuinely new and which are SEO repackaged, separated by the measured evidence on what moves LLM citation rates.

## [llms.txt and llms-full.txt: A Sitemap, Rewritten for Language Models](https://troll-tech.co.uk/notes/llms-txt-the-ai-sitemap.md)

*22 May 2026 · 5 min read*

Why two plain-text files have emerged as the LLM-era counterpart to sitemap.xml: one a curated index of what matters, the other the whole site inlined as Markdown for single-fetch ingestion.