.tip

Aug 27, 2026 · one of the small things

Prompts live in the repository with a version and a changelog line

A prompt edited in a dashboard has no history and no review, and no way to tell which version produced last Tuesday's bad outputs.

prompts/classify-ticket/v7.md
prompts/classify-ticket/CHANGELOG.md   # v7: added the refund-vs-chargeback example, +1.5 on eval

Log the prompt version on every call's trace. When an output is wrong, the version tells you what the model was told.

ai-engineeringengineering-practice

~/tips/today — 2026-10-19

~cat tips/today

Never build an index on a live table without CONCURRENTLY

postgresqlmigrations

A plain CREATE INDEX takes a lock that blocks every write to the table for the whole build. On a big table that means minutes of outage that look like a hung app.

CREATE INDEX CONCURRENTLY orders_customer_idx ON orders (customer_id);

It's slower and can't run inside a transaction, so you'll have to tell your migration tool. If it fails halfway, it leaves an invalid index behind, so check pg_index.indisvalid and drop it before you retry.

↵ open y yesterday l ls /tips

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