One of my favourite lock-free, hash-table talks is by Dr. Cliff Click, ex-Azul Systems, presently at H2O.ai, from 6 years ago: https://www.youtube-nocookie.com/embed/WYXgtXWejRM

Rust's implementation of Google's SwissTables is pretty trippy, as well: https://blog.waffles.space/2018/12/07/deep-dive-into-hashbro...

Whilst Clojure, Scala, Erlang, and Haskell use Hash Array Mapped Tries https://en.wikipedia.org/wiki/Hash_array_mapped_trie and its lock-free variant, Ctrie.

Speaking of exotic data-structures used widely: HAProxy's creator u/wtarreau invented Elastic-Binary tree that powers HAProxy's caches and schedulers.

Presentation: https://www.youtube-nocookie.com/embed/fXuYWqWsdFQ

Blog: http://wtarreau.blogspot.com/2011/12/elastic-binary-trees-eb...