The comments here are full of people bucking against this advice. I've worked at TWO companies now where people said NO we want to use SQLIte in dev. Both switched in under a year despite fierce internal opposition. Everyone had changed their tune once they hit growth in users and complexity. Why? Because being ideologically right is not as nice as being sure you're writing code that works.

The fact is if you have a serious site there's a good chance SOME specific feature will start looking appealing ( maybe array values, JSON , window functions, a pg extension...). These features are written because people use them, we aren't all writing dead simple CRUD apps. Or you your ORM will interact with one slightly differently than the other. I don't expect to convince any of you doubters, but the first time you get a bug in prod that slipped through the testing process but really could have been caught in dev, you'll ask yourself why you weren't using pg there too.

There's no sane reason to complicate your life by running two databases unless you either have a dead simple app, or are one of the jabbering idealists I see on here. Productive programmers simplify the problem and minimize their tech stacks.