.tip

May 7, 2026 · one of the small things

Commit .env.example, never .env

.env goes in .gitignore. The example file next to it, with every key and a placeholder value, gets committed, and it's the only documentation of your configuration that stays up to date.

DATABASE_URL=postgres://user:pass@localhost:5432/app
STRIPE_SECRET_KEY=sk_test_...

Add a startup check that fails when a key from the example is missing from the environment, and a mystery crash becomes a one-line error.

securitydeveloper-experience

~/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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