When it comes to running content management systems there are always more reads then writes (hopefully) so caching becomes of utmost importance for a successful WordPress install. With a product as mature as WordPress there are tons of options out there, from APC object caching to static HTML file generation to caching with CDN distribution management.
WordPress on Heroku
With 18% of the internet running off WordPress and between 50–100k sites launching on it every day using WordPress seemed the obvious choice. Where to host it however, was a more difficult decision. With such a large market share comes a myriad of deployment options. From large turnkey blog as a service providers like WordPress.com and WP Engine to complete roll your own WordPress.org on AnyHostUSA. In the end I decided to go with a happy median, running WordPress on a PaaS cloud provider (I hear it’s web scale that way) for the extra flexibility. This also has the benefit of giving me an excuse to learn more about the internals of cloud services.