Can we use BitBucket for Ignition deployment

Can we use BitBucket to deal with deploying Ignition applications and provides some best practices for setting up development and testing workflow?

A good starting point:

Is there any sort of 7.9 equivalent to this? I know the resources in 8 are much more straightforward, but we are looking for some way to rev control one (or hopefully, just a few) binaries in 7 if possible.

No, the vast majority of project and global resources in v7.9 are stored in binary form in the internal database. So not are the resources not broken out into files, they are fundamentally unfriendly to source control diff operations.