For one project I keep notes in a git repository so I can grep them for stuff later. At the beginning of every month I create a 2018-11.md or whatever and keep

For one project I keep notes in a git repository so I can grep them for stuff later. At the beginning of every month I create a 2018-11.md or whatever and keep the notes going there all month. For another project I keep notes in a wiki. It's not as easy to search as git, but I still refer to it for things I did months or years ago.