"I found out that you guys just build an amazing mobile app for your e-commerce venture, I heard you are using Symfony 2 for your back-end APIs. How did you make it that fast?" This is not very different that what I was asked some months back. The answer is we use a Service Oriented Architecture (SOA) where all back-end service follow the REST architecture to communicate with all the clients. The client can be built in any language as longs a they can do HTTP calls. Lets look at what Symfony 2 bundles you can use to build a similar scalable, fast and cacheable REST APIs.