&quot;The example application proved nonetheless that building an application without middle tier, based on AngularJS + MongoDB, is possible and very straightforward&quot;<p>Making the minimal featureset in the article happen seems like a necessary but not sufficient condition to demonstrate that this technique is &quot;straightforward&quot;. Certainly, if implementing that app <i>isn&#x27;t</i> straightforward then anything more complicated is doomed - but reading through the RESTHeart docs does not fill me with confidence that things of realistic complexity will be straightforward.<p>For instance, the RESTHeart &quot;security&quot; layer offers your choice of two different not-remotely-production-ready &quot;toy&quot; identity managers; one that works from a file of usernames &amp; passwords, and one that uses a Mongo collection of usernames and UNHASHED CLEARTEXT PASSWORDS. If you want something better? Well fire up the ol&#x27; Java IDE...<p>I&#x27;d also quibble with the entire premise - RESTHeart _is_ a middle tier. It&#x27;s one that depends on YAML configuration rather than boilerplate code to accomplish the features used in the article, but it&#x27;s still a Java app that deploys separately from Mongo.