To mitigate these limitations and reduce write pressure, we’ve migrated, and continue to migrate, shardable (i.e. workloads that can be horizontally partitioned), write-heavy workloads to sharded systems such as Azure Cosmos DB, optimizing application logic to minimize unnecessary writes. We also no longer allow adding new tables to the current PostgreSQL deployment. New workloads default to the sharded systems.

"wow, we've made our postgres so good and fast... by moving heavy workloads to a NoSQL database engine". Truly mind-blowing, OpenAI. Just like their LLM service, not even their technical staff can stop themselves from lying and writing misleading statements.

The only interesting part could have been what they use for caching... but of course they don't give any details at all. And all the rest is already well-known DBOps stuff... and basically all automatic with stuff like cnpg.