How to manage data of a website with the DBMS PostgreSQL?

[KianUReeves]

Hello!

Two friends and I are developing a web application and for the creation of the website we used WHMCS. We expect that we will have a large amount of data to store and manage.
For the management of the database we decided to use a database. We decided to use the DBMS PostgreSQL, because it is open source, objectrational and included in our Linux distribution.
Another advantage is that PostgreSQL is based on the SQL standard (ACID-compliant, DDL) and offers many extensions.

The development is already very nerve-racking and has partly brought us to our limits, but somehow we managed it together when we had no other choice.
We don't even want to imagine how all this will be with the data streams when the web application takes off and gets the job done.
Therefore we are looking for solutions to better manage the data or database. We also see it as problematic to manage so much data on one computer and would like to have a cloud-based solution.
However, it is not so easy to find suitable software that is compatible with PostgreSQL. So we researched for a while and read in another community that there are DBaaS providers who take care of this.
For example there is the provider Aiven for PostgreSQL, which is also cloud based. But we are not sure if we can backup, manage and restore all data streams with this provider if something happens.
There are also other DBaaS providers, but this one would be open source.

Did any of you have experience with an open source DBaaS provider and can report or even recommend it? Or should we look for other solutions?