Domain Modeling in F# with Types

HN people recommend it as an eye-opening talk whose domain-modeling ideas carry over to other languages and make a strong compiler feel like a coding partner.

Scott Wlaschin's NDC talk on using statically typed functional programming, F# in particular, to model a business domain. Types are used to represent the domain precisely and to encode business rules so that illegal states cannot be built, with the compiler acting as an instant unit test.