A fuse protects the wire, not the appliance. It is sized to the cable, so that the cheap part gives way before the thing you cannot easily replace does. I find that a useful way to think about limits in software.

The equivalents: a timeout on every outbound call, a quota per caller, a circuit breaker that stops calling a failing service (the pattern Michael Nygard popularised in Release It!), a bulkhead so one slow dependency cannot use every worker. In each case the limit is deliberately…

A boring checklist for any code that accepts text from the internet. None of it is clever, and many incident write-ups I have read come down to one of these lines being skipped.

1) Limit size before doing anything else with the input. Parse nothing you have not bounded.
2) Normalise encoding once, early. Mixed Unicode forms and look-alike characters cause quiet bugs.
3) Use parameterised queries. Do not build SQL by pasting strings together.
4) Escape at the point of output, for the context it…

What is the most boring technology decision that saved you the most trouble?