Netflix has 100+ production clusters running Cockroach DB
cockroachlabs.com
cockroachlabs.com
That's quite a few, but if production incidents and issues are rare, might not be too big of a headache.
If high QoS or 9's of uptime is required, the upfront investment in thoroughly and effectively monitoring any new service is a significant engineering endeavor.
One of the bigger burdens from large fleets like this is fleet management and maintenance, specifically managing upgrades. If you have a story around that, you're in good shape.
Most of the excitement comes from moving workloads onto crdb from PG, where it's not uncommon to have workloads with right-leaning indexes or workloads. This class of problem is solvable, but it will catch some people by surprise.
At the end of the day, having a database that can absorb punishment from as small as a few dozen QPS up to millions of QPS is a big reliability win, esp with the self-healing characteristics of the database technology.
How does it compare to the overhead and experience of DIY postgres?