Channel balances, gateway routing nodes, non-advertised channels, buffer capital, source routing, onion routing, bridge channels, and atomic multi-path payments. Take a dive into the tech behind Lightning routing with Bryan Vu and the Lightning Labs Blog.
Don’t forget to check out the full article to see the graphics and explore other great work over at the Lightning Labs Blog:
https://blog.lightning.engineering/posts/2018/05/30/routing.html