We have 14 servers and counting running the frontend captcha service, we have a high uptime which you can observe here: https://portal.prosopo.io/status
We have extra provisions for enterprise clients to provide rock solid SLAs for every use case.
The db in question is our data store for event that we use for aggregated features such as traffic analysis and ml. This service lags behind our realtime services so we can deal with some downtime if necessary