I see this take a lot, and vehemently disagree. An OO language with record types and pattern matching expressions, plus a vague hint of union types in the futu

I see this take a lot, and vehemently disagree. An OO language with record types and pattern matching expressions, plus a vague hint of union types in the future; is not a functional language. Depending on who you ask, it's either a quasi-functional OO language or a bloated OO language. I used to be in the first camp, now I lean towards the latter. Over time, projects morph into the average of their framework. If you started off badly, if it survives long enough eventually someone will refactor it into something acceptable. If you start off using FP features, eventually they will be eroded away; through friction with external dependencies, or later developers being less invested in the paradigm. In both cases you're usually left with an inconsistent codebase. When people say that C# is morphing into F#, my usual thought is 'have you ever seen an FP project?' Take some time and read some FP codebases, and compare them with a typical C# codebase. (side-note: one of the most widely used FP language for web development is elixir. There are a few good open-source elixir projects you can read to get a feel for the structure. Almost all elixir projects follow the same structure, and it's about as anti OO/SOLID as possible, yet still conforming to a vague onion architecture.)