I decided to look at the recent commits, and..., well, could not believe my eyes, PostgreSQL just got integrated!
PostgreSQL opens the door for (novice) admins to create forums based on NodeBB, on cloud platforms that don't support MongoDB or Redis, or where such support is too expensive.
With PostgreSQL support, the admin does not need to create and maintain a database on an instance - instead for a similar cost he may opt for PostgreSQL as service. In Amazon AWS for example, the service comes with automated backup and restore. The integration is quite speedy with low to moderate effort (basically reading few AWS documents and following examples).
Besides that, PostgreSQL offers additional features over key-value database, so future releases may benefit as well.
This amazing achievement was made possible by @Ben-Lubar, with help from @julian and the rest of the NodeBB team.
Congratulations on this fine release.
I am grateful for your work and dedication!