This version uses Webpack to create a completely isolated frontend that overrides rake assets:precompile. It provides everything you could possibly want in your development workflow.

About 2 hours using vue-cli with the vuejs-templates/webpack template.

Assuming you have foreman installed (gem install foreman), use the development Procfile to launch Rails and Webpack together:

foreman start -f Procfile.dev

Then visit localhost:5000 to see your frontend in action.

• Only 1 pipeline: Sprockets is now completely out of the picture, as are any of Rails' other view-related features
• CSS preprocessors & extraction: SCSS (or other preprocessors) plus PostCSS for autoprefixing and other transforms, all extracted into a single CSS file
• Automatic spritesheet generation: Images and other files can also be referenced via the module system and smaller images with be base64 encoded and bundled directly into HTML, JavaScript, or CSS
• Lint-on-save: Catch errors and style violations before they catch you
• Unit & E2E tests: Unit tests for every component and E2E tests in multiple browsers
• Primed for mobile: Since the frontend is already independent of the backend, porting it to mobile with Cordova could be relatively trivial
• Extremely extensible: The Webpack ecosystem is very rich, so it's likely anything else you might want to do with your builds is possible

• Very, very complex setup: Setting all of this up by hand would probably take several days and maintaining it will require some knowledge of Webpack
• Not progressive: The entire frontend is now a SPA, so familiarity with Rails will not help designers or backend developers build simple pages