Question is in the title - if anyone has experience working in a bakery that would be great. Thanks!
Most small bakeries use small rotary mixers (like a Kenwood that stands as high as a man) that handle batches up to about 100lb - using a dough hook for bread.
The really big bakeries use trough mixers with blades that turn along the length of the trough. A typical batch is around 600lb.
Given the high volume required for commercial bread making, I doubt any except the small mom and pop shops still knead dough by hand. From what I've seen (35 or so years ago...) visiting a small town bakery shop serving a few thousand people, they had a machine to do the work even then, a large steel vat in which all the ingredients are dumped and mixed using a metal arm and a motor.
They still made special doughs by hand (cookies, cakes, etc.), but the stuff for normal breads was made mechanically.
I asked a friend baker to help him for a night, so I could improve my home bread. They use machines to knead the bread as they prepare a lot of dough (25-30 kg of flour at a time).
The machines I've seen have two speeds (speed I and speed II) and you can set the timer for both (my friend puts 5 minutes on I then 20 minutes on II) so the mixer switches automatically from one to the other.
The white bread is kneaded using a rotatory mixer, while for whole grain he uses a machine with two "hands" that knead the dough from bottom-up (the same is used for brioches and croissants).