I also made my own variable speed diaphragm water pump for our boat's water pressure. The VSD options on the market were notoriously unreliable, so I took one of the best non-VSD pumps with a pressure switch and drove it with a custom board + software. This also meant if my controller failed (which it never did) I could switch back to the original pressure switch.

https://github.com/johnboiles/openvsd