i3 is a window manager that can outcompete anything you can do with vim splits or a tool like tmux/screen. It's whole existence is based around putting windows in the right place at the right time.
Ranger is a vim-like ncurses file browser. I think it's genuinely one of the most underappreciated tools in programming. The ability to hjkl through your file system, with quick marks, with vim-style cut/paste, with visual mode, with about 20 other things that I use daily which just means that no other viewer comes remotely close.
My typical flow has between 4 and 12 terminals open, with the bulk being ranger->vim, which allows me to easily navigate complex project structures. The others are usually make, or htop, or some ssh.
I'll usually have a couple of web browsers open in another workspace as well. i3 tiling extends to all applications.