Take the Azure Cosmos DB Cloud Skills Challenge

 A free, self-paced course by Microsoft gives you the chance to expand your knowledge of Azure Cosmos DB as well as earning a certification.

Azure CosmosDB is Microsoft's mutli-model distributed database for supporting workloads at scale. As we examined in "Azure CosmosDB for PostgreSQL Reaches General Availability", by adding support for PostgreSQL CosmosDB has broken free of the NoSQl model and spanned over to the Relational. This move has rendered Azure the first cloud provider to offer its own single database service that supports both relational and NoSQL workloads from PostgreSQL, MongoDB, and Apache Cassandra.

https://www.i-programmer.info/news/150-training-a-education/15936-take-the-azure-cosmos-db-cloud-skills-challenge.html