If you have complex interactions sequence diagrams can be a hugely helpful communication tool. I use https://sequencediagram.org/ https://sequencediagram.org/ q

If you have complex interactions sequence diagrams can be a hugely helpful communication tool. I use https://sequencediagram.org/ https://sequencediagram.org/ quite often. It's a free, in-browser tool that lets you create/edit/export diagrams using markup. Takes some getting used to but I much prefer it to dragging arrows around manually.