I’ll never understand what people see in prologue

What do you recommend instead for web development with Nim?

My guess is the GP misunderstood and was speaking about the Prolog programming language, not the web framework mentioned.

To address your question, the only complete back end web framework for Nim that has significant traction (that I know of) is Jester. Karax for the front side. The Prologue framework looks interesting though.