I mean we have built a nice ORM for FoundationDB, but eventually we found several bugs in it and we just didn't write to our indexes correctly or put several indexes in the same subspace. Then we started to migrate our data (we were so crazy that moved large chunk of our production data already!) and we found that our migrators are also have problems. Basically our data was not consistent at all.

There are almost no easy way to ensure that everything is OK.

Also I have fear that we probably deleted something and there are no way to prohibit modification of certain keys.