My problem with this article is the entire strategy for delivering data. A JSON file? That's probably the worst way I could think of: a CSV file would have been better. Part of the reason why databases exist is to handle exactly the problem the author is posing. There are already tools in place in SQL databases that track diffs for TB db's, and the authors could simply export patch files which would be far easier to analyze for inconsistency.

It really bothers me that the article is like "wow, check ou this awesome utility that helps us with a huge problem" instead of really thinking about "how did we get this huge problem and is there already a solution."

It just reeks of inexperience.