Years ago I learned to code in PHP/MySQL, never really using a framework. I made some attempts to use CakePHP and Symfony but never liked them much. When I wanted to build my first big project, I looked for something like Rails in PHP but couldn't find anything. I did find Django, though, which looked cool. Since Python was more similar to PHP than Ruby, I learned Python and used Django. Eventually I found Django too…
I spent nearly 15 minutes on the parse website but still can't figure out what it does. All I see is that it's an open source version of the Parse API. But what is the Parse API? Since you've used it before, would you care to elaborate on what the Parse API does?
They provide a nice dashboard for creating Mongo collections (which they call Classes).
You write "cloud code" in JavaScript. You can write beforeSave and afterSave functions which are triggered before/after you save a document. You can also write "cloud functions" which execute within parse-server and interact with the database.
The result of this is that you can perform a lot of heavy lifting and consistency logic in one place, "the cloud." That way you can build clients in multiple languages (like an iOS app, Android app, web app) that only need to worry about their platform specific details.
Their original value prop was for building mobile apps, but since the ecosystem is pretty mature with a client in every language, I find the benefits extend to writing multiple clients for any purpose.