Do we apply modern technology in building our custom guns? You bet. To be honest, it does not come easy to me. I received my training in the 80’s and the novelty of CNC machines and Cad designs was pretty foreign and unaffordable to the small shop where I worked. My first inclination is always to reach for a hacksaw and file when making a part. In the early 2000’s I worked for a short time for Sigarms and became friends with a manufacturing engineer. He really opened my eyes and introduced me to computer aided drafting (CAD) and to basic CNC (computer controlled) machining.
In our shop we have 2 CNC milling machines. The perception often is that you just push a green button and the machine spits out a part. That is pretty false, as it is not that easy. But I must say, the machines have given us the opportunity to make our guns more unique and the quality more uniform. Parts, such as our front sight ramps, scope mounts, barrel bands, grip caps, extended tangs, and many one of a kind projects we make on those machines. I utilize a 3D cad software almost daily and it has also turned into somewhat of a hobby of mine The question may arise, does this technology quench the creative process of a craftsman? In my opinion, the opposite. 3D Cad allows to look at new designs and alter them before ever machining it. Also it is possible to assemble parts in the computer and play with the geometry and function.
CNC improves the quality, saves time and also allows for making parts that would be most difficult to do on manual equipment.
Small shops such as mine can rarely justify the investment into state of the art equipment, such as wire and sinker EDM (electric discharge machining) machines. So it makes sense to outsource certain parts to specialized machine shops. 
The picture is of our scope rings wire edm machined.
Despite modern technology, at least 80% of my time is still spend on the bench. What can’t be re-placed with technology is an understanding of traditional designs, and the ability to make a rifle “flow” with style and grace.