Great question — answering as the UphillTech team:
There are quite a few workflows you can use here. 1. Task runners If you're using either Gulp or Grunt locally for development, there are libraries out there that will upload your files to the store through API credentials of a Private App that you have to create. Most work by uploading the files you change, using a watcher. grunt-shopify grunt-shopify-upload gulp-shopify-upload (it's my favourite since I use Gulp but has a known issue that sometimes it stops uploading files and you have to restart it). 2. Official Shopify Theme Kit Theme Kit is a cross-platform CLI tool that was built by Shopify Employees. It can run on windows/linux/OS X. You can read more about it on Shopify Blog or...
Full answer by Juan Ferreras: https://stackoverflow.stackexchange.com/a/38814778 (CC BY-SA 3.0).
Need it done for your business? UphillTech.