Production postmortems and architecture notes: Redis cluster mode, Postgres row-level security, document parsing, and the infrastructure underneath.https://aadityakushwaha.comenhttps://aadityakushwaha.com/writing/agent-review-gaphttps://aadityakushwaha.com/writing/agent-review-gapA study of 33,596 agent-written PRs found most receive no recorded review. The diff isn't what's missing — the reasoning is.Mon, 17 Aug 2026 00:00:00 GMTPostmortem — agent workflowshttps://aadityakushwaha.com/writing/elasticache-cluster-modehttps://aadityakushwaha.com/writing/elasticache-cluster-modeRedis and ElastiCache Serverless are not the same database. Four assumptions broke at once, and the one that took the platform down wasn't a Redis assumption at all.Mon, 17 Aug 2026 00:00:00 GMTPostmortem — ride-hailing platformhttps://aadityakushwaha.com/writing/law-as-default-denyhttps://aadityakushwaha.com/writing/law-as-default-denyCold email is regulated differently in every country, and the regimes disagree. Putting that in a wiki page produces confident guessing. Putting it in a function produces a verdict, a citation, and a diff.Mon, 17 Aug 2026 00:00:00 GMTDesign — outbound compliancehttps://aadityakushwaha.com/writing/one-pdf-at-a-timehttps://aadityakushwaha.com/writing/one-pdf-at-a-timepdfium crashes two ways: one instance per document SIGTRAPs, and concurrent calls from a single instance segfault. The fix is a global mutex, which means the parallelism has to live somewhere else.Mon, 17 Aug 2026 00:00:00 GMTPostmortem — document parserhttps://aadityakushwaha.com/writing/rls-below-the-applicationhttps://aadityakushwaha.com/writing/rls-below-the-applicationPostgres row-level security turns tenant isolation from a promise the code makes into a constraint the database enforces. Then a permissive policy quietly hands one admin every tenant's rows.Mon, 17 Aug 2026 00:00:00 GMTArchitecture — multi-tenant LMShttps://aadityakushwaha.com/writing/the-backup-that-failed-in-ninety-millisecondshttps://aadityakushwaha.com/writing/the-backup-that-failed-in-ninety-millisecondsThree weeks of nightly backups, every one an instant failure, every one recorded and never surfaced. Found the same afternoon as a dual-WAN link that had been down long enough to stop being redundancy.Mon, 17 Aug 2026 00:00:00 GMTAudit — self-hosted infrastructurehttps://aadityakushwaha.com/writing/two-ways-a-parser-lieshttps://aadityakushwaha.com/writing/two-ways-a-parser-liesA fabricated zero reads as a correct extraction. So does an accuracy score measured on the fields you matched rows by. Both make the number go up.Mon, 17 Aug 2026 00:00:00 GMTDesign — document extractionhttps://aadityakushwaha.com/writing/the-document-your-editor-rewrotehttps://aadityakushwaha.com/writing/the-document-your-editor-rewroteSix data-loss bugs in one course editor. Five were about saving. The sixth was the editor deleting content on open, and it is still open.Sun, 16 Aug 2026 00:00:00 GMTAudit — course editor