Every table in one vector index
Eight business tables, one HNSW index, and a rule: no embedding is ever computed inside a request. The projection, the loops, and the worker.
An import that tells you what it will do
A school's data arrives as spreadsheets nobody cleaned. The hard part is not parsing them: it is saying what will happen before it happens.
One bank entry, forty invoices
A Swiss QR payment advice groups forty payments into one booking. A parser that reads the entry amount reconciles nothing. How to split it correctly.
Your editors are trusted. Sanitise anyway.
A tag allow-list cannot say an iframe must point at YouTube. The attribute filter that can, and the wrapper span that quietly bypassed it.
One hundred and sixty characters, none of them accented
One non-GSM character drops the limit from 160 to 70. Transliteration, a measured budget, and knowing what must never be truncated.
Buying a domain from Django
A 1990s XML protocol, an MD5-of-MD5 signature, a DOCTYPE you must not parse naively, and calls that debit an account. What the wrapper has to get right.
The flag that was written and never read
A Stripe webhook set is_active to False and nothing on the request path read it. The middleware that fixed it, and the four exemptions it needs.
Class 1 is assets, except where it is liabilities
Every accounting tutorial hard-codes class one as assets. Under SYSCOHADA it is liabilities. What has to become data when the standard is a variable.
CORS for a write surface
Allow-Origin star is fine for a public feed and catastrophic for a write endpoint. A per-form allow-list, exact origin matching, and the preflight trap.
Most account deletions are a mistake
A delay, two typed confirmations, counted losses, and a memory of what was published. The details that decide whether erasure destroys the right thing.
Certificates for domains that do not exist yet
Caddy issues a certificate at the first handshake for a name it has never seen. Without the right ask endpoint, that is a free certificate mint for anyone.
An offline queue that loses nothing
Queueing JSON is easy. Queueing a form whose photos were already uploaded is not. Negative placeholder ids, and the errors you must never retry.