If you're looking beyond uptime + certs, we do functional + visual browser testing at https://ghostinspector.com/. Lots of folks use it for monitoring their website or application (in additional to their CI process). We have a free tier that includes scheduling. [Disclosure: I'm the founder]
Nice work! We have a similar feature built into Ghost Inspector: https://ghostinspector.com/#visual-regressions -- It includes a tolerance setting so you can basically say "I only want to hear about it if the screenshot changes by xx% or more." Effective visual regression testing at scale is tough though and is really more of a secondary feature for us.
If anyone is interested in other solutions, ImageMagick has a nice "compare" tool built-in. There are also plenty of open source projects like Huxley, PhantomCSS, etc. I recently saw a demo of Applitools Eyes (https://applitools.com/) and it's quite powerful (though it's a paid service).
The author initially sets up this piece to be a criticism of quantum mysticism. However, as the post goes on, it seems to become a dismissal of quantum mechanics all together -- based on an obvious bias for determinacy.
I'd first make sure that MongoDB is locked down in your firewall. Only open port 27017 to the IPs that need it (app, secondaries, etc).
I've found Mongo's authorization setup to be pretty unintuitive, but you can find some information here: http://docs.mongodb.org/manual/core/authorization/ (IIRC, you need to setup the permissions first, then set "auth=true" in mongod.conf and restart the service.)
Very nice! I've been using PhantomJS 2.0 for a while now at my automated browser testing startup: https://ghostinspector.com/ (It's been available to build from source for a couple months.)
It has a few lingering bugs (for instance, some issues with file uploads), but overall, it's a nice improvement over 1.9.x. The JavaScript engine is much newer and the rendering is improved.
Looks nice! I created a service called Ghost Inspector last spring that runs PhantomJS under the hood: https://ghostinspector.com/
It's not open source, but there's a free tier and lots of nice features built in like video recording, screenshot comparison and a GUI editor.
If anyone is planning to write PhantomJS scripts directly, I strongly recommend checking out CasperJS: http://casperjs.org/ -- It gives you a really nice layer on top that makes Phantom much more wieldy.
The author has posted a follow up here -- http://drew.roon.io/responsive-retinas-strike-back -- that offers some alternatives for getting around the extra download issue (which a number of people brought up, including @ricardobeat in the comments).