title: What are the core differences between Firebase and Express?
body: <p>Right now I'm exploring how to write an API using Express and MongoDB. I'm also using Angular to do my routes and views. I know Firebase and AngularFire can make it so I can bypass using Express all together (or so I think) and have my app be realtime. </p>
  
  <p>In <a href="http://www.christopheresplin.com/single-page-app-architecture-connecting-to-firebase" rel="noreferrer">this article by Chris Esplin</a> he states that he could not give up Express because he needed it to write promises instead of callbacks for cleaner code when using his npm package 'Quiver-Invoice' with Firebase, Stripe and MailChimp's Mandrill service. </p>
  
  <p>In <a href="https://stackoverflow.com/questions/14673929/using-nodejs-with-firebase-security">this SO post</a> the poster says they need to use Express &amp; Node for the ability to send emails out. I assume this is impossible if one uses only Firebase with Angular.</p>
  
  <p>Also I have seen people talk about differences in authentication and security differences between the two here <a href="https://groups.google.com/forum/#!topic/firebase-talk/WF9gf--A3Qo" rel="noreferrer">https://groups.google.com/forum/#!topic/firebase-talk/WF9gf--A3Qo</a> </p>
  
  <h2>Question(s)</h2>
  
  <p>So what are the core differences between Firebase and Express? </p>
  
  <ul>
  <li><p>Is it possible to build an API around Firebase like I can do in Express + MongoDB?</p></li>
  <li><p>Is it possible (or will it be possible soon) to customize the Firebase server like one can with Express?</p></li>
  </ul>