Integrating Drupal into an existing site to manage comments
Though this is an old question, and it probably depends on what your project is using other than Drupal, from what I hear there are some decent &quot;hybrid&quot; CMS options out there.
You can combine Drupal with NodeJS or AngularJS.
Since you said you don't want Drupal for the design, that is called &quot;headless/decoupled Drupal&quot;.
Here is some more information: Headless Drupal: The What, Why and How