As a routing node operator (c-otto.de) in the #LightningNetwork, I wonder which implementations are responsible for the transactions, how routing decisions are made, how pathfinding works.

For example, I suspect that WalletOfSatoshi uses some centralized solution: larger chunks of fresh inbound liquidity from their node (for example, because my node routed a large transaction TO their node) are quickly drained (most likely used for transactions originating from their node).

How do other larger nodes find routes? Do you know what BitFinex or Binance do to route users' withdrawals? What about other services/wallets? How do merchants cash out / pay their bills? How are transactions from/to LOOP or FixedFloat users routed?

I could look up the routing code details in LND and CLN, but my gut feeling is that there's more going on. Please provide insights, if you have any!