Yeah, a couple years ago I built a system that undergirded what was at the time a new product but which now generates significant revenue for the company. That system is shockingly reliable to the extent that few at the company know it exists and those who do take its reliability for granted. It's not involved in any cost or reliability fires, so people never really have to think about how impressive this little piece of software really is--the things they don't need to worry about because this software is chugging along, doing its job, silently recovering from connectivity issues, database maintenance, etc without any real issue or maintenance.

It's a little bit of a tragic irony that the better a job you do, the less likely it is to be noticed. (: