Follow this advice with caution. Dropping foreign keys is effectively giving up part of the C in ACID. It should be done with very, very open eyes to the downsides. I'm not sure the author is selling the "when" side of this very well. Migrations are "hard" because the database is forcing you to handle correctness criteria that are easy to ignore. "Lock contention" is the database covering your sloppy ill-thought out application code from doing the Wrong Thing. Yes, of course, you take a minor performance hit in exchange for consistency, but how many of us actually work on applications where that trade off is the wrong one? Developers are frustratingly superstitious about scale and their need to do it.
The data will very likely outlive the application that created it. It's almost guaranteed to outlive your tenure on the team. Viciously guarding its correctness solves all the problems that not guarding it causes.
The data will very likely outlive the application that created it. It's almost guaranteed to outlive your tenure on the team. Viciously guarding its correctness solves all the problems that not guarding it causes.