The developer feedback loop

Workflow is really important to me, because I hate faffing around and like to be as efficient as possible. Regardless of how complex your build process is or how you run your tests or what text editor you use, the developers feedback loop is something that everyone has.

:w<enter> <cmd + tab> <cmd + r>

This is my feedback loop. I write some code, save it and want to preview the changes in a browser. I write in Vim so to save, I type :w<enter> - other text editors typically have a save shortcut like <cmd + s>. After saving, I want to see the results so I switch over to Chrome and refresh the page. This takes less than half a second so my feedback loop is pretty tight.

If I had to reach for my mouse, move up to the top of the screen, click File > Save, move the mouse to the task-bar, find the Chrome icon, click it and then move the mouse back to the top of the screen, find the refresh icon and click it, my feedback loop for previewing a change could be a few seconds rather than a few tenths of a second.

Is it worth the time
source: xkcd

This whole idea of tuning process reminded me of this xkcd comic which shows how long you could spend making a routine task more efficient without wasting your time. Quite incredibly, according to this chart, I could spend a whole day optimising the “save, switch, refresh” feedback loop because it’s almost certainly something that’s done more than 50 times a day.

Live reload

If this is true, I should optimise my already tight feedback loop even futher. I could do this by removing the refresh step entirely and this can be accomplished with LiveReload which watches for changes in the file system and automatically injects them into the browser. I’ve tried to use this in the past without much luck, but recently found a nice way of integrating it with my workflow, on this very blog


Grunt is a Javascript task runner that allows you to automate stuff like compiling Sass and concatenating and minifying JS. I also use it to compress images and build this site before deploying it. Grunt has a bunch of core plugins for things like watching files and can be told to automatically reload the page when your files change using LiveReload. This is accomplished by setting the livereload option in your Gruntfile.js on a per file-type basis.

module.exports = function(grunt) {
	watch: {
		css: {
			files: ['assets/css/main.min.css'],
			options: {
				livereload: true,

As long as you have the LiveReload Chrome extension you should be good to go and your can start reaping the benefits of time saved by never having to refresh a page again.

The only downside I find when using Grunt is that it’s a lot slower to compile CSS than using Ruby and sass watch - the concept of fine tuning workflow is the real takeaway here though.

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