We build 350 microservices, we used all types of databases that existed, we even had a team that decided to make their own object database because after an extensive research "all current ones aren't good enough".
Every sprint people would discuss architecture and we should improve it, because we had full freedom to eliminate our technical debt.
We researched and developed our own "patented" distributed RBAC subsystem.
Product is still in alpha and it seems to me its too slow to release on market.
It's for B2E sector and the backlog for any decent sale is still to big to have a meaningful usage.