Until today, if I wanted to profile my neovim startup time I would alias nvim to something like nvim --startup ~/nvim-startup.log. After running the editor for a bunch of times, I would open the log file and manually inspect the timings.
I was not satisfied with this approach and I wanted something better. Today, I found stevearc/profile.nvim after a rather quick googling around.
The setup is straightforward and requires just a copy paste, other than installing the plugin. Then, by running neovim with an environment variable the profiling will take place. It’s possible to pass any argument to nvim as usual.
NVIM_PROFILE=start nvim
By pressing F1 as soon as neovim finishes loading, the plugin will produce a json file. The json file, usually named profile.json, can be uploaded in any Chromium browsers’ DevTools by going into the Performance tab, clicking on the load icon and selecting the profile.json file. It is also possible to use chrome://tracing, but I find the experience being much better with the DevTools.