Here's a VERY HARD to find bug that declare(strict_types=1)
found:
The Problem: Some note attachments were getting lost in the system. We could see them on GCS, but the API was returning 404s. We couldn't figure out why this was the case for a couple of weeks and the problem was only sporadically reported (not part of the main workflow).
As soon as I turned on strict typing, the problem manifested itself:
class NoteAttachmentHelper