I wrote an article expanding upon Gaffer's article about fixed timesteps. It covers game state double buffering and interpolation, correct input handling, and the benefits of fixed timestep in general

https://jakubtomsu.github.io/posts/input_in_fixed_timestep/

I also posted this tweet about interpolation which got good responses for whatever reason:)
https://x.com/jakubtomsu_/status/1820048637268795634?s=19