Fun fact, the maximum number of hops a LN payment can have is 20 hops.

This 20-hop limit is enforced by the ChaCha20 stream cipher required by BOLT#4.

As the name suggests, ChaCha20 can encode a maximum of 20 layers of cyphers (20 payment hops).

Elle has the best technical blog in lightning. She's basically writing a protocol book as a blog and I hope she turns it into one.

Is "Elle Mouton" a pseudonym meaning "she sheep"?

When book?