A perfect Lighthouse on Astro and Cloudflare
The playbook behind kairn.in: static-first Astro, inline critical CSS, subsetted fonts, sized images, viewport prefetch, no default client JS, and sane cache headers.
Notes from the trail.
A cairn is a small stack of stones that tells the next person they are on the right path. These are ours: how we build AI agents, web platforms and products, written down so you can walk it faster.
Agents that know when to stop
An agent that cannot stop is a liability. How we give every agent a step budget, a typed stop reason, a way to hand off to a human, and evals that check all three.
Read the note 
Evals before features
Why we write the test set before the AI feature, how to build a useful 30-example golden set in an afternoon, and how to make CI refuse regressions.
Designing Kairos for small studios
One space per client, approvals as real objects, invoices beside the work, and a short list of things we left out on purpose. The thinking behind Kairos.
How Treviko uses AI on the catalog
Product copy, attribute tagging and search for a home-essentials store, with a person approving every change before it reaches a shopper.
Why we're called Kairn
A cairn is a small stack of stones that tells the next hiker they are on the right path. That idea shapes how we write, build and document, and why we use exactly one red.
One waymark when we find something worth marking.
Engineering write-ups, AI field notes and product decisions from Kairn Labs. Roughly twice a month. No tracking pixels.
