I prefer C# for the back-end and using a dynamic language (inc. TypeScript) for building UI's, which I find is a highly productive combo which has gotten a lot

I prefer C# for the back-end and using a dynamic language (inc. TypeScript) for building UI's, which I find is a highly productive combo which has gotten a lot nicer with .NET Core where it's now a nice dev experience using any IDE/text-editor on any platform to build apps that runs flawlessly on Linux/Docker/etc.