I used Prologue for backend and Karax-Karkas-Kraut for frontend.
People say good things about Mummy so I would give it a shot.
What is Karax-Karkas-Kraut again?
It's a combo of Karax, Karkas, and Kraut.
Karax is... OK, just kidding :-)
Karkas is a flexbox-driven library that helps with layouting and components in Karax.
Kraut is a library that helps with frontend routing. It provides helpers that allow to work with routes and params instead of a raw hashpart string.
I did a talk about those on a NimnConf.