Using tmux + tmuxp[1] you can load a pre-configured session and execute arbitrary shell commands for the session, window and pane. I use this to set up shells and editors in the correct dirs (and/or hosts), load lang environments, set env vars and source some zsh aliases and functions that I only want per project. The end result is that I can set up my dev environment (shells with different environments, neovim windows, test runner, various linters I don't wannt integrate into nvim) with a single "tmuxp load <project>".

edit: That is just my personal killer feature, obviously having a terminal setup that is consistent cross platform and great for stream processing is a given.

[1]: https://github.com/tmux-python/tmuxp