ajustino.dev / notesEngineering write-ups and anonymized case studies.https://ajustino.dev/enThe horizon that lost the westhttps://ajustino.dev/notes/cordoba-horizon-rebuild/https://ajustino.dev/notes/cordoba-horizon-rebuild/A precomputed artifact served confidently wrong answers every evening - 20 of 64 horizon sectors were zero. How impossible geometry gave it away, and how a 13-hour rebuild became a 15-second deploy.Fri, 14 Aug 2026 00:00:00 GMTThe API was broken, so I traced the map that workedhttps://ajustino.dev/notes/effis-broken-wfs/https://ajustino.dev/notes/effis-broken-wfs/How geo-hazard's wildfire ingestion went from a WFS that returned SQL errors to live data - tracing the official EFFIS viewer to a different mapfile, a catalog of OGC quirks, and the asyncpg limit the first real payload found.Sat, 04 Jul 2026 00:00:00 GMTFrom a TLE to a contact windowhttps://ajustino.dev/notes/tle-to-contact-window/https://ajustino.dev/notes/tle-to-contact-window/What happens between downloading two lines of orbital elements and telling a ground station when a satellite will rise. SGP4, elevation masks and pass geometry.Thu, 02 Jul 2026 00:00:00 GMTColophonhttps://ajustino.dev/notes/colophon/https://ajustino.dev/notes/colophon/How this site is built, and why it ships almost no JavaScript.Tue, 23 Jun 2026 00:00:00 GMTA Postgres job queue instead of a message brokerhttps://ajustino.dev/notes/postgres-queue-vs-broker/https://ajustino.dev/notes/postgres-queue-vs-broker/How apsis runs scheduled jobs and a transactional outbox on plain PostgreSQL, and when I would not do it.Tue, 23 Jun 2026 00:00:00 GMT