Write a couple hundred lines of your favorite language and throw it up on Google App Engine. Have the code query all relevant threads/comments and store them in GAE's free memcached service. It should fall perfectly into the free tier, and if not the $300 free trial should last you a full year. Finally have the angular2 app query your GAE project directly and you should be looking at < 50 ms loads of much more efficient json data.

Wish I worked for Google, but I just like GCP (currently migrating my company's infrastructure to it).