For example: right now I have problem with how to use aliases. I don't fully get them and I'm not good enough at kotlin to understand it from reading Exposed source code (I tried). How do you use alias to create function transforming ResultRow to Domain data?

You can try to check wiki https://github.com/JetBrains/Exposed/wiki/DSL#alias

Ah, thank you but I read wiki. In fact I did it many times and it helped me in simpler cases but not in the advanced ones. Does this mean we can except documentation soon or is this further down the roadmap?

Some part of documentation is written already but it's far from completeness and the the process goes not very fast

At least the code of library is high quality so I can learn by reading it. Thank you for your answers