Hi there,
guess there are plenty of companies out there with success stories. Personally I have been quite septic when I was asked to use MongoDB for a government project in the area of tax income prediction. We stared small more in terms of an POC, but the success came faster than we thought and we had to scale out. Luckily this was a really easy task with MongoDB. That it is purely made for it but it is one of its pros.
An other project, last year was in the area of health / hospital software with faily high security and HA targets. Also this was easier that thought in the beginning. The more I use MonogDb the more I like it.
Personally I think the success story of MongoDB is just in its Beginning but this is my own opinion. The best thing you can do it to give it a try. But please do not make the same error like me. First get a very good understaning of the document model than design your DB. Many calls for help I get can be boiled down to a design which was obviously make be some one who was still thinking in relations instead of documents.
Have fun and enjoy, as soon as you climbed the hill and start thinking in documents you have passed the line. :-)
It is surprising that not so many companies do as they do at MongoDB. Maybe because of the burden which needs to be taken to integrate a third-party tool for testing. Yes it costs resources but as MongoDB proofed - it pays off. I need to deal with many DBMSs. MongoDB has by far the least amount of patches - this in depth testing is surely one of the reason for this good result.
Good news to hear!
We just finished a fairly big IoT project where we needed to ship a replicated database which was fast, easy to deploy and reliable. We tried other DBs but none was so stable to be shipped with a standalone application completely black boxed to the customer. I was septic in the beginning but after 800 installations in 2 month we have no complains. Also not from early adopters which run now for appr. a year.