What is the reason of you trying to go for the microservices-based architecture?
Personally I think you can go a long way with a centralised database for a long time. I mean, it could be backed by Amazon RDS which is pretty high performance and fault-tolerant.
Phrase your needs a bit further!
Do you have million of users or a team of hundreds of engineers, or are you a young startup?
If you do like some heavy processing/machine learning/big data stuff, sure - run that as separate services and plug it in through in an API Gateway, but I don’t see why you wouldn’t store most things in a centralised database until your service really booms. If/when it does, you’ll probably have capital to comes with that to tackle those issues.
Here’s two articles that resonates a lot with me personally.
I stand strongly against premature optimisation - I prefer shipping features for the people using the services!