Can you please describe the implementation of this system, and the problems encountered recently, in more detail?

Which database systems are involved in the "database migration" described in the support center article? Please list at least the product names and versions.

What was the nature of the "refactor"? What programming languages and implementations were involved, for instance?

What exactly happened during the "database migration"? Was there any data loss?

What sort of backup infrastructure is in place?