DP-420 study guide
DP-420 · Work through your exam, one topic at a time.
The Microsoft Certified: Azure Cosmos DB AI Developer Associate is an intermediate-level Microsoft certification for developers who build and optimize applications on Azure Cosmos DB. Microsoft positions the role around cost-effective, high-performance, scalable applications that use Cosmos DB as the system of record for agent memory, conversation state, retrieval indexes, grounding data, and application data. The credential was renamed and its level updated to reflect the evolving role of Cosmos DB developers, effective October 6, 2026, with no action required from existing candidates. The exam assesses three areas: designing and developing database solutions; securing, optimizing, and deploying database solutions; and implementing AI and analytics capabilities in database solutions, including retrieval and RAG patterns, agent memory systems, and Fabric integration for analytical querying. The DP-420 study guide has 3 sections and about 1,062 words.
01Design and develop database solutions
The NoSQL API scales per logical partition, so the partition key is the single most consequential decision. Choose a property present on every item, with high cardinality, that appears in your most frequent filter.
378 words, about 2 min02Secure, optimize, and deploy database solutions
Control-plane roles (Owner, Contributor, Cosmos DB Account Reader) let you manage the account but grant no data. Data-plane access uses Microsoft Entra ID with the built-in SQL roles (Cosmos DB Built-in Data Contributor or Data Reader) assigned through a role definition and assignment, or a resource token broker pattern that scopes a user to a partition key through stored procedures.
338 words, about 2 min03Implement AI and Analytics capabilities in database solutions
Azure Synapse Link enables a columnar analytical store on a container, letting Synapse Spark or serverless SQL pools query operational data without consuming transactional request units. Enable it per container (ideally at creation), choose the sync mode, and remember the two clear separations: analytical data is read-only and cannot serve transactional reads, and analytical queries do not touch the transactional partitions.
346 words, about 2 min