We have an idea that eventually we can attract developers of various nationalities. to the nodeBB projects.
A set of instructional videos with subtitles created regularly, for example explain codes of nodeBB core, making plug-ins, optimize nodebb config for production, even teach nodejs , etc ...
Then publish them on YouTube.
In addition to these films, the set of documents to be prepared that teach developers how to develop nodeBB and place it on the project's wiki.
Then ask your users to translate these documents and subtitles in their own language, Also send news of this series of tutorials to students in their university.
For example, we can do this for the Persian language.