It's Tuna here, the creator of MonoSketch, a tool to help you attach diagrams to the code.
Something like this

             ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─          
              Edge Region 1                                           │         
             │                                                                  
                   ╭──────────────╮   send msg to ╭──────────────╮    │         
 /\_/\       │     │╭─────────────┴╮   websocket  │╭─────────────┴╮             
( o.o ) ◀══════════╰┤╭─────────────┴╮◀═══════════▶╰┤╭─────────────┴╮  │         
 > ^ <       │      ╰┤    Envoy     │ sub to this  ╰┤Gateway server│            
                     ╰──────▲───────╯   channel     ╰───────▲──────╯  │         
             │              ║                               │                   
              ─ ─ ─ ─ ─ ─ ─ ║ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┼ ─ ─ ─ ─ ┘         
 /\_/\                      ║                               │                   
( o.o ) ◀═══════════════════╝                               │                   
 > ^ <                                                      └───────────────┐   
   │      ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┼ ─ 
   │     │Main region                                                       │  │
   │                                                                send msg│   
   │     │   ┌──────────────┐               ┌──────────────┐          to all│  │
   │         │┌─────────────┴┐     send     │┌─────────────┴┐        GS subs│   
   └─────┼──▶└┤┌─────────────┴┐ channel msg └┤┌─────────────┴┐              │  │
              └┤    Webapp    ├──────────────┴▶ Admin Server ├─────┐        │   
         │     └───────┬──────┘               └──────────────┘     │        │  │
                       │ store                                     │        │   
         │             ▼ message                           route to│        │  │
                   ░░░░░░░░                                 channel│        │   
         │         ░Vitess░                                  server│        │  │
                   ░░░░░░░░                                        │        │   
         │                                              ┌──────────▼───┐    │  │
                                                        │┌─────────────┴┐   │   
         │                                              └┤┌─────────────┴┐  │  │
                                                         └┤Channel Server├──┘   
         │                                                └──────────────┘     │
                                                                                
         │                                                                     │
          ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ 

ASCII diagram is cool to see but not easy to work with. Before MonoSketch, I tried several tools but none of them satisfied my need. I want a tool simple to use, has very good UX, and most importantly, is free. That's why I create MonoSketch, a tool you don't feel you are working with characters but with a powerful diagram editor like draw.io.

I know there is a long way to go to be able to achieve the level of draw.io or any non-trivial diagram editors. I will try my best to keep improving the app.