Working with BackBlaze B2 and ActiveStorage gave me a flashback to when I spent months adding mock implementations of S3 versioning to Fog. It was a lot of tedium working out exactly how S3 would respond because actual API responses often conflicted with the documentation. API errors that Amazon documented as being impossible would happen sporadically, but regularly.
PRs for those interested:
* https://github.com/fog/fog/pull/672
* https://github.com/fog/fog/pull/681
I kinda miss working on Fog and Rubber.