[sideeffffect]

* Immutable-first

* Immutable/persistent collections in standard library

* Machinery to "modify" immutable deeply nested case classes/sealed traits. You have the copy method, you have lens libraries. Very easy and comfortable to use.

* Expression oriented. if/try/etc expression can be bound to a variable

* less characters to write the same idea/program, while not losing readability

* better tooling: Scalafmt is ubiquitously used, supported in IntelliJ and is very good. Scalafix (a linter which can also fix some issues automatically) is used a little bit less, but is also good.

* build tools: while I don't like sbt, Mill is a so much better build tool than Maven or, even worse, Gradle. Then there is also scala-cli, which is not a build tool, but can work like it, if you have a simple, single-module project (i.e. no sub-projects/sub-modules).

[gf000]

Also, the collections API is the best out of any language I have used!

[linotype]

Thank you, this captures most of these. I’d also add the excellent libraries from Twitter like Algebird and ability to do a lot of data processing with types at scale using Spark.