Two pieces of infrastructure went onto the site this weekend. Both make a similar choice—static and deterministic even/over dynamic and server-bound—and both turned out smaller than I expected. Quick tour of each?

(Not worth mentioning but nice: new sidenotes; KaTeX for math in posts.)

The new feature images

Stock photography is bad. AI illustration looks like everyone else's AI illustration. Much as I would like to commission art for a personal blog, that would be unhinged. So with Claude's help I built a small Cloudflare Worker that takes a post slug^[1], hashes it, and renders a deterministic pixel-art SVG from the bits.

The system has roughly the shape of a tiny pattern language. Each image is two to four non-overlapping panels, laid out by binary space partitioning^[2] with a 24px outer margin and 16px gaps between them. Each panel runs one of ten strategies — grid, quilt, checker, strata, columns, field, plus the more characterful gravity, chaotic, scatter, clusters — and draws from a vocabulary of seven atomic marks:

About forty percent of panels run a secondary pass with a different mark on a palette subset—producing a sense of two systems negotiating inside one rectangle.

The math underneath is just bit reading. SHA-256^[3] of the slug gives 256 bits of pseudo-random output, and the renderer doesn't really generate from that seed so much as address into it. Every design decision—strategy, mark, palette pick, density, cell size, which cells get filled—pulls a few bits off the stream, treats them as a number, and uses that number to look up an answer from a fixed list of options. Read three bits, get a number from 0 to 7, pick one of eight strategies. Read five bits, get a number from 0 to 31, pick a palette entry. This is what makes it deterministic.

For example, when a post has a particular tag, the math weights the tag color eight-to-one, the two color neighbors five each, with other brand colors and a muted accent once each — total weight twenty.