I'm a fairly junior developer at Braintree. I spent two months this summer working in our West Coast office pairing with one of our most senior developers. I spent almost the entire time at the keyboard. The senior developer provided guidance, a sounding board for ideas, kept me from diving too deeply into rabbit holes, provided context about the choices made in the project, etc. It was one of the most rewarding experiences I have had as a software developer.

Another thing to mention is that we generally rotate pairs fairly regularly. A developer will work with others with very different levels of experience both in general and within Braintree.