[fiddlerwoaroof]

I’ve had the exact opposite experience as a full-stack dev: backend code generally has a more or less straight-through code path from the request handler to the response, on the front-end a user can be interrupting your processes at any moment.

[sanderjd]

Probably depends on scale. I think front end is the harder part of getting something decent working while backend is the harder part of getting it working well under load.

[deanclatworthy]

Yep this is the point. Back-end for sure is simpler if you are not operating at any meaningful scale. As soon as you start tackling the problems mentioned in my OP, things get (much) harder.