> Source? This hasn't been my experience. Going on 10 years of heavy Node.js ecosystem involvement, immutable data enthusiasts are exceedingly rare. Immutable.

> Source? This hasn't been my experience. Going on 10 years of heavy Node.js ecosystem involvement, immutable data enthusiasts are exceedingly rare. Immutable.js is relatively popular and immutable records and tuples are a stage 2 TC39 proposal. From what I've seen, immutability is mostly popular on the frontend, probably because functional programming had a huge impact there. It's also popular in other languages (FP or FP inspired generally, so OCaml, Haskell, Scala, Elm, Elixir, Rust) that are relatively close to the web ecosystem. > Plus, this is const vs let, which is a reach to call "immutable data". We're not talking about object properties. I'm not sure what you mean here.