One more thought.

Make sure the case/carcass is perfectly square as you glue it up. Drawers are problematic otherwise.

I've created some built ins where the casework gets slightly out of square during installation and it adds some complication to getting the drawers to perfectly fit and the drawer front to line up perfectly.

Square is good.

My process:
1) Buy the drawer slides
2) Build the case
3) Measure and build the drawers