When working with Azure Cosmos DB, one of the primary design activities you will undertake is appropriate partition design. Using partitioning in this way enables Cosmos DB to make good on its promise of “limitless horizontal scalability.”
Throughput configuration and careful partitioning choices can often avoid hot partitions, and you can learn all about throughput, partition key design and other hot topics in my course, https://acloudguru.com/course/dp-420-designing-and-implementing-cloud-native-applications-using-microsoft-azure-cosmos-db.
This is similar to the existing synthetic key partitioning capability in Cosmos DB, but with far less complexity for design development and implementation.
By default, Azure Cosmos DB divides up provisioned throughput equally across all physical partitions.