I would like to develop a very simple web application. Is there something similar to Flask from the Python world for Kotlin?
I know that, for example, there is a Kara frame, but it looks abandoned.
For this purpose you can use any java web infrastructure.
Personally, I recommended Spark Java . You can also use undertow , rapidoid , ratpack , etc.
Another option is Spring Boot , which is also lightweight, see post on memory consumption ,
This is Kotlin’s excellent (curated) kindness list: https://github.com/KotlinBy/awesome-kotlin , and there are some web frameworks.
Great place to visit from time to time and see what's new.