> They had begun work in 2011, but they rejected all of the existing document databases (such as MongoDB or Riak). In 2013 they decided to work on version 2.0 of their software, which would be a complete re-write, but they decided to continue to keep JSON strings in PostGres.

That's speaks in their favor, in my opinion. We actually consciously moved the way MongoDB -> PostgreSQL JSONB column, and are pretty happy with that. Sorry, original author, but if you recommended us to use shiny new databases like MongoDB or Riak, we'd probably think of you as a young and inexperienced engineer.

Although I agree about Design Patterns. For example, you'd use/no use ReactiveX regardless of whether you know about Observer pattern or not.