It is very rare to encounter a stack of software that work together in perfect harmony to a developer. Many developers have to rely on development boxes to do some pieces of their development tasks such as database testing, using cache servers, and so on.

There has been a lot of effort put forth to minimize this, thanks to the software such as Vagrant. I mentioned Vagrant early on, in which we demonstrated how to bootstrap an AWS EC2 instance from a configuration file. The real power to it, however, is bringing the developers closer to the environment that it will be deployed under.

For example, imagine a team that works on a Ruby on Rails application. Each developer uses a Macintosh since it can handle Ruby natively. Many developers, however, may use different versions of Ruby and write their code that way. During deployment, this is not communicated and the code is shipped out onto a CentOS box, which uses a much older version of Ruby. The code has a high...