Been an SRE and DBA for almost 20 years and the only truth in tech I firmly believe in: use whatever you want in a new project. Build fast and get it out. Once you have paying users, hire old dads like me to move you to Cassandra or Vitess or TiDB or something, or dont and just pay the bills for mongodb and laugh all the way to Series C.
I wouldn't start a new project with MongoDB, I'd probably use ScyllaDB, and i'd spent months getting the data model just right while you launch and get paying customers.
We're seeing a convergence of document DBs adding relational features, and relational DBs adding document features. At this point I find the best of both worlds to simply be PG with JSONB.
I wouldn't start a new project with MongoDB, I'd probably use ScyllaDB, and i'd spent months getting the data model just right while you launch and get paying customers.