Writing
The Context Window.
The Sandcastle Labs newsletter. What happened in AI discovery, lessons learned, and tips you can use.
Every essay on this page goes out as an issue. It's operator-grounded writing about what we're shipping, what we're seeing in the market, and where the AI consensus is wrong, including the results that came back empty.
Arcs
An arc is a bounded narrative inside the chronicle. Each one has an ending question it is built to answer. Posts inside an arc come from one or more series (build logs, essays, updates). When the question is answered, the arc closes and we move on.
Active
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Collimer Season 1
activeJune 2026 – ongoing
Opens with the first Collimer build logs, before the product had a public name. Establishes the bet, the question, and the season's stakes. Subsequent posts track the build through to the collimer.com launch and beyond.
Ending question
Did our bet on the GEO space hold up after first contact with the market?
21 posts so far →
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The Unattended Studio
activeJuly 2026 – ongoing
Founding 100 Days ended with the studio finished building itself. This arc is what happened next: the machinery it built kept reporting success while quietly doing nothing, and the work of the season is finding out which parts can actually be trusted to run unattended.
Ending question
Can a studio run on machinery it built itself, without someone watching it every day?
18 posts so far →
Closed
Recent issues
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We stopped selling Collimer as its own product
· 9 minSandcastle Labs discontinued Collimer's self-serve plans and folded its marketing into one brand. The product didn't get smaller. It stopped competing with us for attention.
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August 2026: twenty releases, and five bugs in the number we sell
· 4 minCollimer shipped twenty releases in three weeks, roughly one every working day. Five of them fixed problems in the score itself, and a correct fix to our own site quietly switched off the pipeline that sends this letter.
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Naming Collimer: an optical metaphor, a multi-agent naming sprint, and a GEO bet
· 8 minCollimer is named after the instrument that turns scattered light into one aligned beam, chosen through a multi-agent naming sprint and a bet that a coined name is worth more in the agent-search era than a searchable one.
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Engineering with AI means checking its work
· 8 minBuilding faster with AI agents means more of the output ships unverified by default. Three catches in one week show what checking, not prompting, actually buys you.
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Build the machine, then hand someone the keys
· 7 minA small AI-native software studio scales by building loops that collaborators can run, not by adding headcount. The unit that compounds is the loop.
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The first letter: where Sandcastle Labs stands, May 2026
· 4 minSite V1 shipped, the chronicle published its first five posts, and Collimer hit v1.0.0 in a three-day agent-fleet build. The first monthly letter from Sandcastle Labs.
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How the Chronicler works
· 6 minWhy a solo studio built an AI-assisted publishing pipeline to share what it is learning, and the human edit gate that keeps it honest.