After reading the linked article I am a bit puzzled. I am absolutely unable to imagine how you can work with a codebase of 1.000.000+ lines using an iPad and Vi

After reading the linked article I am a bit puzzled. I am absolutely unable to imagine how you can work with a codebase of 1.000.000+ lines using an iPad and Vim. 1.000.000 lines. That is on the order of 50 developers spitting out code for 5 years. The largest projects I have worked on are an order of magnitude smaller and even for this size I am unable to imagine how you could replace working on a solution with 50 projects in Visual Studio with just using Vim. Not to mention coordinating 10, 20 or 50 developers if everybody is sitting under different trees. At least for me given my experience in developing software this makes absolutely no sense.