Microsoft DP-420: Building AI Applications with Azure Cosmos DB

Last checked October 22, 2026 against the official Microsoft exam page.

1. Question 1Design and develop database solutions

   A globally distributed application must guarantee that reads never lag writes by more than five minutes or a fixed number of versions, while keeping latency lower than strong consistency. Which consistency level fits this requirement?

   1. AEventual
   2. BStrong
   3. CBounded staleness
   4. DConsistent prefix
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   Correct answer: C

   Bounded staleness lets the team configure a maximum lag in time or versions, which gives a predictable freshness guarantee with lower latency than strong. Eventual has no bound, and consistent prefix guarantees order but not a time limit.

2. Question 2Secure, optimize, and deploy database solutions

   An application running in Azure must access Azure Cosmos DB without storing account keys in its configuration. Which approach is recommended?

   1. AUse the account connection string in a public GitHub repository with sample code files
   2. BShare the account's read-write key with every developer so each can test locally
   3. CEmbed the primary key in the compiled application binary so it ships with each release
   4. DUse a managed identity with Microsoft Entra ID authentication and disable key-based authentication
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   Correct answer: D

   Managed identities with Entra ID remove long-lived secrets from application code and allow access to be governed by role assignments. Embedded or shared keys create exposure that identity-based access avoids.

3. Question 3Implement AI and analytics capabilities in database solutions

   An application wants to store vector embeddings and query them with a vector index. Which container-level element must be defined when the container is created?

   1. AA separate Azure Cosmos DB account for each embedding dimension, each with its own throughput
   2. BA nightly script that regenerates the embeddings from the source documents and writes them back
   3. CA cloud-based image classifier hosted in Azure Machine Learning to tag photos
   4. DThe vector embedding policy that describes the vector path, dimensions, and data type
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   Correct answer: D

   The vector embedding policy and matching vector index are part of the container definition, which the vector search depends on. The other options are unrelated to the container configuration.

4. Question 4Design and develop database solutions

   Which consistency level is the default when a new Azure Cosmos DB for NoSQL account is created?

   1. ASession
   2. BEventual
   3. CBounded staleness
   4. DStrong
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   Correct answer: A

   Session is the default and guarantees read-your-own-writes for a client session. Strong and bounded staleness are stricter options, and eventual is weaker than the default.

5. Question 5Secure, optimize, and deploy database solutions

   A reporting service needs read-only access to items in one container and must not be able to write data. Which control provides the narrowest appropriate permission?

   1. AGrant the service owner rights across the whole Azure subscription scope
   2. BGive the service the account's primary key to use for data access
   3. CAssign a data-plane role-based access control role that grants read access only
   4. DAllow read-write access to the container and rely on code to avoid unneeded writes
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   Correct answer: C

   Data-plane role-based access control assigns read-only data roles that can be scoped, which enforces least privilege. Full keys and subscription ownership grant far more than the service needs.