Zinc

We're in the process of moving to a SOA (service-oriented architecture), and each of our services run on a cluster of EC2 boxes behind an ELB. Our services are built primarily with Go and Ruby, depending on the requirements. Amazon EC2

We use Vagrant for our development machines and to run our Chef integration tests. Vagrant

We wrote our own image processing, resizing, and snapshotting service in Go to allow our clients to send photos and GIFs to each other. Files are stored in S3, resized on the fly using OpenCV, and then cached in GroupCache before being served to clients.

Go allows it all to be quite fast and efficient, and entirely non-blocking on uploads! Go

We use Ruby for our APIs, coupled with Rails. We also use it for scripting and other open source applications. Check out https://github.com/cotap/stacker and let us know what you think! Ruby

All of our web apps are built using BackboneJS. Keeps our code clean and organized, and keeps the page refreshing to a minimum! Backbone.js