You will lose the best candidates with an onerous coding challenge.
Our process, which has been heavily influenced by debate on r/experiencedevs on reddit involves a short phone screen, a 30 MINUTE coding challenge, a tech interview consisting of pair programming, and a non-tech interview with management. Very light.
The coding challenge is a FILTER only. It's not to evaluate who to hire, but instead it's to filter who not to continue interviewing.
You learn a lot during pair programming in a short period of time, including personality and team fit. We let them drive and we just watch and discuss. The assignment is to fix a bug, and refactor the code the caused the bug.