Not sure if I should ask this here. Could somebody tell how to use both the vi editor and the terminal horizontally stacked upon one another like in the video, I could understand though how you are splitting the editor. It makes the dev process a lot easier
Josh is using tmux in these videos. Coincidentally we have a whole course on tmux here on Upcase if you want to learn more 
Thanks, loved that switch mode, productive for the dev process, I thought he was using screen or some commands on the iTerm