How a hidden PostgreSQL CHECK constraint silently aborted an entire CRM workflow

Engineers at Elevare Digital discovered that new contact records in their ARIA CRM system had stopped enrolling in follow-up sequences due to a CHECK constraint on a database table. The constraint, added to an enrollment_tracker table, restricted a region column to only five predefined values, but the table was later repurposed as a general-purpose tracker accepting a wider range of regions. When a trigger attempted to insert a record with an unlisted region value like 'southeast', PostgreSQL rejected it and silently rolled back the entire parent transaction, meaning no contact was created at all. The core problem was that the column name alone gave no indication of its restricted scope — only the constraint itself encoded that assumption, and no one had read it. The fix involved checking allowed values inside the trigger function before attempting the insert, logging invalid entries separately rather than aborting the parent write.