> There are so many better options if you want a good type system I am looking for basic type checking to prevent me from doing stupid things and catching bugs

> There are so many better options if you want a good type system I am looking for basic type checking to prevent me from doing stupid things and catching bugs at "compiletime" instead of runtime. Typescript interfaces with their structural typing do the job just fine. I think people are underestimating the power of ecosystem. I use JS daily. Deno allows me to use it on the server as well without doing crazy things. You have been able to do something similar in Java for a very long time with Mozilla Rhino (and now GraalJs) but without the same level of comfort and convenience.