As Oracle states, "A record declaration specifies in a header a description of its contents; the appropriate accessors, constructor, equals, hashCode, and toString methods are created automatically.

A Roslyn analyzer to enforce some good practices in C# in terms of design, usage, security, performance, and style.

Runtime performance is improved by 25% to 40% depending on if the composable is being instantiated or reused. Allocations are also reduced by 35% to 48%. More info here.