Kidding aside, I just have 2 gaming monitors on either side of my MBP, in landscape. A screen for monitoring prod, a comms screen, and a code screen. When needed I slide out a coding window to another monitor.
I also use the extra desktops for my calendar and my task list. Three-fingers slide one way to see my calendar in maximized Safari, the other way to look at tasks in maximized Trello.
About vertical coding, I tend to think that if you need to go vertical to understand the code, it's already too long. Note I don't mean it must fit in landscape, I'm saying if it doesn't AND you need to see it in vertical for it to make sense, that's a smell. YMMV.