I actually think MongoDB highlights the challenges in this article. Namely: - Tremendously popular database, a huge success by open source standards! - Their

I actually think MongoDB highlights the challenges in this article. Namely: - Tremendously popular database, a huge success by open source standards! - Their open-source API has been used by Amazon to create their biggest competitor (DocumentDB). Or alternatively any cloud provider will help you spin up pre-built images with MongoDB installed (no path to monetisation). - Have not (yet) been able to turn it into a profitable business, with large (and widening) losses recorded the last 3 years (at what appears to be the height of it's popularity). - To create revenue they need a huge sales team (I've heard the pitch and seen the cost!). They not only have to bid against competing technologies, but also their own free tier! - This resulting in... Mongo having to change their licence to create a profitable business. 23.15B market cap though - but they have had to ultimately change their licensing plan to find a profitable way forwards.