[dotancohen]

  > Or if customers only use it right before a federal deadline for filing
  > forms, or at the end of the quarter when it's time to generate reports.

You're right. How would you suggest to defend against these situations?

I personally like to version my APIs, but that is robust insofar as code changes, not for database changes.

[hinkley]

The other responder liked monorepos for this. It’s not perfect, but it does help with making sure you had all of the code to search from, and once in a while the commit history adds additional clues.