15 · Images

Photographic series forced a separate image processing pipeline, and one that runs outside the site — because rescaling a photograph on every request would waste CPU time, which at the edge comes in a measured portion.

A photograph goes in once and comes out in three forms. The body variant: longer edge around two thousand pixels, compression chosen so that no difference is visible on screen. The share card: the aspect ratio social networks require and a hard weight limit, with quality stepped down until the file fits. The file name is always the entry's identifier, so there is nowhere any record of what belongs to what.

The share card is the element whose absence is only visible from outside. Without one, a link looks like bare text on a social network and simply does not get clicked. It is the part of the infrastructure that serves not present readers but future ones.

The app icons are generated too, rather than drawn by hand — from a monogram and colours supplied as arguments. This came out of the fact that a full icon set for a progressive web app is several sizes in two variants, and a single missing one breaks installation: the background script fetches the whole list at once and the first missing file aborts the operation.

The more general conclusion: anything that can be computed while preparing content should be computed then. At the edge, CPU time is a resource rather than an assumption.