That's why we have software testers. Most of the stuff I build nowadays is server backend stuff and mobile. For server backend this runs on strong machines. No

That's why we have software testers. Most of the stuff I build nowadays is server backend stuff and mobile. For server backend this runs on strong machines. No problem. For mobile I use a device. For desktop stuff we have a minimum machine which we test. Also IDE's have profilers integrated where you can see if you take up too much RAM or CPU. There's no need to suffer slow performance to create apps that run in constrained resources. You can have more than one computer too. Even as a one person shop.