200 searchable records (heavily searched and essential to the app) kept getting deleted from their index on our search engine.

we couldnt figure out why, but we wanted to resolve this quickly next time it happens so we got them back up, duplicated the index, and whenever we see they got deleted we resync them from the replica.

Eventually i found that there was a piece of code that updates the index by deleting everything from it and uploading everything back but it was buggy in doing the latter.