[gqewogpdqa]

Yeah, I think MongoDB went through a set of steps - atomically consistent at document level (which is fine for many apps as you have most related data in the single document anyways) - atomically consistent within a collection - and now, with MongoDB 4.0 and higher (released in 2017? 2018? whatever, a long time ago), MongoDB supports full transactional consistency across documents, collections, and shards. It took them awhile, but they got there.