The best replacement for backend is back-end.

The best alternatives to backend are rated as following:
★★★★★  back-end
★★★  frontend
★★★  frontend web development
★★  frontend database
★  back end

Your alternative for backend is not listed? Suggest!
Speaking about backend, one probably shouldn't forget about angularjs.

Other search terms related to backend and their ratings are:
★★★★★ angularjs
★★★ angular
★ xbmc frontend
★ frontend
You have in mind a companion for backend and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of backend in all years. Click on graph for more.
backend
back-end
frontend