Position: Senior full-stack developer or whatever
Category: .NET
English level: upper
Years of experience: 11

I've created C# to JS transpiler and use it for my full-stack web development. You can read about it (among other stuff) and even watch some videos on my "resume website." The URL is in "Contacts and resume" section of my profile, for I'm not allowed to put it here, in public area.
In the old days I mostly did server-side Java. In recent years I've learned some "modern" web development stuff and have been working on my own "startup" project. The project underwent several full rewrites with following technology progression: traditional Spring MVC/JSP Java --> full-stack JavaScript --> lightweight Java + TypeScript --> Kotlin + Kotlin/JS --> Go + GopherJS --> and finally I've settled on C#.
Desired project types, by decreasing level of desire :)

1) Creating developer tooling or something like that. Maybe internal tooling (compiling, code analysis, deployment, test automation, etc.). Maybe even some “low-code” or “no-code” solution for external customers.

2) Something where following can be applied: logic programming, constraint solving, SAT, Differential Datalog, Differential dataflow. Not that I’m an expert in these areas, but I want to become one :)

3) Full-stack web development. I think I'll be able to do "usual" full-stack stuff like ASP.NET Core + EF Core + TS + React. But see also section "Achievements" below.