field notes codename
60 notes filed under ABACUS, newest first. Same rules as the rest of the pile: a codename, a theme, and no internals.
The requirement was absolute: a replayed stream had to be byte-identical to what the live system emitted, or nothing built on the replay could be believed. It nearly was. A full-scale comparison across millions of records showed a small…
Two constraints define reproducibility here, and they arrived years apart. The first is that the executable which ran must be regenerable from a pinned state of the record. So a manifest binds the built artifact's content hash to the exact…
elsewhere
Each codename is a project. The theme is the class of problem the note is about — the same theme recurs across projects, which is usually the interesting part.