I think that depends a lot on how you define "backend". Writing code to take requests, verify inputs, put things in databases, pull things out of databases, wor

I think that depends a lot on how you define "backend". Writing code to take requests, verify inputs, put things in databases, pull things out of databases, work with third party APIs, etc isn't too bad and the tech isn't moving particularly fast, so it's easier to keep up than frontend. The way backend code takes in requests and handles them and returns responses hasn't really changed that much in the last 10 years. But if your definition of "backend" includes devOps and cloud computing like edge functions and building using hosting-provider-specific features like AWS's featureset, then "backend" is moving significantly faster than frontend, and it's a hell of a lot harder to learn as you go.