About a year and a half ago (written June 2013) we moved from dedicated servers over to AWS. Thanks to AWS, we no longer have to think on a server level. Instead, we think of everything as a cluster of instances, and an instance is essentially a virtual server where we don’t have to worry about the hardware. It’s a relief to not have to worry about the hardware behind the instances.
The clusters we have are: WWW, API, Upload, HAProxy, HBase, MySQL, Memcached, Redis, and ElasticSearch, for an average total of 80 instances. Each cluster handles the job that its name describes, all working together for the common goal of giving you your daily (hourly?) dose of image entertainment.
Below is a diagram of how they all work together:
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.
We liked a lot of things about Heroku. We loved the build packs, and we still in fact use Heroku build packs, but we were frustrated by lack of control about a lot of things. It’s nice to own the complete stack, or rather as far down as AWS goes. It gave us a lot of flexibility and functionality that we didn’t have before. We use a lot of Amazon technology.