I have to work with Gerrit, which requires amending existing commits after they’ve been pushed to the remote branch to address comments. I’ll frequently have lots of commits I’m working on above the commit in review. Along with a couple other branches. Every commit also has to compile and pass tests. I’ll frequently go git rebase -i --autosquash paired with git fixup. I’ve made mistakes before that are hard to untangle. With jj it’s just jj edit <change-id>.

Or if I want to insert a commit between two others it’s just jj new -A <change-id> to create a new commit after the change id (but BEFORE the previous change that was after the commit). With git I’d need to commit then rebase, put it in the right slot and recompile, rerun tests, re-edit. If I work on a branch I’d need to rebase, possible merge conflicts. jj just puts me on that commit then helps me manage merge conflicts going up. It’s fewer commands focused on what I want to do and less on the tree like git.