Microsoft Certified: Azure Cosmos DB Developer Specialty (DP-420) Practice Tests

The DP-420 exam is weighted toward five skill areas, and the 677-question CertCompanion bank is built to match that split. Design and implement data models is the largest area at 35 to 40 percent, covering non-relational modeling, partition key selection, hierarchical and synthetic keys, SQL queries, SDK CRUD and patch operations, and server-side JavaScript. Maintain an Azure Cosmos DB solution follows at 25 to 30 percent (monitoring, backup and restore, and security), then Optimize an Azure Cosmos DB solution at 15 to 20 percent (query tuning, RU cost, indexing, and change feed). Design and implement data distribution and Integrate an Azure Cosmos DB solution round out the exam at 5 to 10 percent each. Note that Microsoft renames and restructures this exam on October 6, 2026, so confirm which version you are booking (details below).

Expect 40 to 60 questions in a 120-minute proctored session delivered through Pearson VUE, online or at a test center. Question formats include multiple choice, drag-and-drop, build-list, case studies, and interactive lab components, and Microsoft does not publish the exact count in advance. Scoring runs on a scale of 100 to 1000, and you need 700 or higher to pass. Most questions target general availability features, though commonly used preview features can appear. If you take a localized version of the exam, you can request an extra 30 minutes.

Microsoft sets no formal prerequisites, but candidates are expected to have hands-on experience developing Azure applications with the Azure Cosmos DB for NoSQL API, including writing SQL queries, tuning indexing policies, and using the C#, Java, or Python SDK. The exam costs about 165 USD, varying by country or region, and the certification expires after one year. Renewal is free through an online assessment on Microsoft Learn, so there is no re-exam fee to stay current. From October 6, 2026, the credential becomes Microsoft Certified: Azure Cosmos DB AI Developer Associate, adding vector search, RAG, and agent memory topics. Start with the 30 free questions, then work through the full 677-question bank until your accuracy holds steady across all five domains.

The Microsoft Certified: Azure Cosmos DB Developer Specialty (DP-420) validates subject matter expertise in designing, implementing, and monitoring cloud-native applications that store and manage data using Azure Cosmos DB. The certification covers the full development lifecycle: modeling non-relational data, selecting partition keys, managing throughput and scaling, implementing the SQL API and .NET/Java SDKs, writing server-side JavaScript (stored procedures, triggers, user-defined functions), and integrating Cosmos DB with other Azure services such as Azure Functions, Azure Synapse Link, and Event Hubs.

The exam was last updated on January 27, 2025, and reflects current platform capabilities including hierarchical partition keys, the integrated cache, Always Encrypted, and Azure Synapse Link with Change Data Capture. Candidates are assessed on their ability to optimize query performance through indexing strategies and cost analysis, implement change feeds, configure backup and restore, enforce security controls using Microsoft Entra ID and Azure RBAC, and automate operations using Azure Resource Manager templates and PowerShell/CLI.

This certification is intended for developers and data engineers with hands-on experience building Azure applications that rely on Azure Cosmos DB for NoSQL as their primary data store. Suitable job titles include Azure Developer, Cloud Application Developer, and Data Engineer. Candidates typically have two or more years of experience working with Azure services and are comfortable reading C# or Java application code, writing SQL queries for the Cosmos DB NoSQL API, and interpreting JSON documents.

Professionals pursuing this certification often work in roles where they are responsible for both the data modeling decisions and the operational health of a Cosmos DB solution—including security, availability, resilience, and performance. It is particularly relevant for those building globally distributed, high-throughput applications such as IoT platforms, e-commerce systems, and real-time analytics pipelines.

Microsoft does not enforce formal prerequisites for DP-420, but candidates are expected to have practical experience developing applications for Azure and working with Azure Cosmos DB database technologies. Specifically, candidates should be proficient with the Azure Cosmos DB for NoSQL API, able to write efficient SQL queries against it, create and tune indexing policies, and use the Azure Cosmos DB SDK (C# or Java). Familiarity with JSON structure and the ability to write server-side JavaScript for stored procedures and triggers is also required.

A solid understanding of Azure fundamentals—including resource provisioning, Azure role-based access control (RBAC), Azure Monitor, and ARM templates—is strongly recommended. Candidates who have completed the AZ-900 (Azure Fundamentals) or AZ-204 (Azure Developer Associate) certification will find much of this background knowledge directly applicable. Microsoft's free learning path DP-420T00 (Design and Implement Cloud-Native Applications with Azure Cosmos DB) is the official preparatory course.

Exam DP-420 is a proctored assessment delivered through Pearson VUE, available both online (remote proctored) and at Pearson VUE test centers. Candidates are given 100 minutes to complete the exam. The number of questions is not publicly disclosed and may vary, but the exam may include multiple question types such as multiple choice, drag-and-drop, build-list, case studies, and interactive lab components. A score of 700 or higher on a scale of 100–1000 is required to pass.

The exam is available in English, Japanese, Chinese (Simplified), Chinese (Traditional), Korean, German, French, Spanish, Portuguese (Brazil), and Italian. If taking the exam in a non-English localization, candidates may request an additional 30 minutes. The certification expires annually and can be renewed at no cost by passing a free online assessment on Microsoft Learn. The exam price is approximately $165 USD, varying by country or region of the testing location.

Earning the Azure Cosmos DB Developer Specialty positions professionals for roles such as Senior Azure Developer, Cloud-Native Application Architect, and Data Platform Engineer—positions that command premium salaries due to the specialized nature of globally distributed database design. According to industry surveys, Azure-certified developers with specialty credentials typically earn between $120,000 and $165,000 USD annually in North American markets, with variation by region and total experience. Demand for Cosmos DB expertise is driven by enterprises building IoT, gaming, retail, and financial services applications that require low-latency, multi-region access at scale.

Compared to the broader AZ-204 (Azure Developer Associate), DP-420 demonstrates deep, focused expertise in a specific high-value technology—making it particularly compelling on a resume for organizations heavily invested in the Azure data platform. The certification is recognized globally and renewable annually at no cost, ensuring that credential holders remain current with platform evolution. It also pairs well with certifications such as DP-203 (Azure Data Engineer Associate) for professionals who straddle application development and data engineering responsibilities.