Designing and Implementing Cloud-Native Applications Using Microsoft Azure Cosmos DBStudy guide
The specialty certification for designing and implementing data models, distribution, optimization, and operations of cloud-native apps on Azure Cosmos DB (NoSQL API-focused) (DP-420).
About Designing and Implementing Cloud-Native Applications Using Microsoft Azure Cosmos DB (DP-420)
Designing and Implementing Cloud-Native Applications Using Microsoft Azure Cosmos DB (DP-420) is a Specialty-level certification from Microsoft. This page organizes the exam scope into a 5-chapter, 13-section study guide and lets you check your understanding with exam-style practice questions. A good flow is to read the chapters below in order, then test yourself via "Practice questions."
Exam domains (approximate weighting)
- Design and implement data models~37%
- Design and implement data distribution~8%
- Integrate an Azure Cosmos DB solution~8%
- Optimize an Azure Cosmos DB solution~17%
- Maintain an Azure Cosmos DB solution~30%
Weights are approximate guidance for the live exam. Each domain is covered in detail in the chapters and sections below.
Official exam information: https://learn.microsoft.com/en-us/credentials/certifications/resources/study-guides/dp-420
1Data models and partition design
- 1.1Non-relational data modeling
Understand non-relational modeling in Azure Cosmos DB for NoSQL: embedding vs referencing, denormalization, multiple entity types in one container, id/partition key/unique keys, default TTL, and versioning.
- 1.2Partition design
Understand choosing a partition key, workload-based strategy, cross-partition query cost, evaluating data/throughput distribution, and synthetic and hierarchical partition keys.
- 1.3Sizing and scaling
Understand evaluating throughput/storage requirements, request units (RU/s), serverless vs provisioned vs free tier, autoscale, database-level throughput, and global distribution cost.
2SDK, queries, and server-side
- 2.1SDK client connectivity
Understand Azure Cosmos DB SDK connectivity modes (gateway vs direct), client singleton, offline development with the emulator, connection error handling, region selection, and SDK logging.
- 2.2SQL queries and data access
Understand Cosmos DB for NoSQL SQL queries (arrays/nesting/aggregation/subqueries/functions), point ops vs queries, patch, Transactional Batch, Bulk, optimistic concurrency with ETag, consistency override, pagination/continuation tokens, 429 handling, and query metrics.
- 2.3Server-side programming (JavaScript)
Understand Cosmos DB for NoSQL server-side JavaScript: stored procedures (transactions within one logical partition), triggers (pre/post), and user-defined functions (UDFs).
3Data distribution and integration
- 3.1Replication, consistency, and multi-region writes
Understand Azure Cosmos DB replication strategy, the five consistency levels, automatic/manual failover, multi-region writes, and custom conflict resolution.
- 3.2Analytical workloads and service integration
Understand the analytical store and Azure Synapse Link, Microsoft Fabric mirroring vs the Spark connector, Change Feed with Azure Functions for denormalization/referential integrity/aggregation/archiving, and Event Hubs and Azure AI Search integration.
4Optimization
- 4.1Query optimization and indexing
Understand index tuning, calculating/retrieving query RU cost, the integrated cache, read-heavy vs write-heavy index strategy, composite indexes, and custom indexing policies.
- 4.2Working with the change feed
Understand processing the change feed (Azure Functions trigger, SDK change feed processor), the change feed estimator, and denormalization/referential enforcement/aggregation persistence/archiving via the change feed.
5Operations and maintenance
- 5.1Monitoring and troubleshooting
Understand response status codes and failure metrics, monitoring Normalized RU Consumption and server-side latency with Azure Monitor, replication monitoring, alerts and resource logs, and monitoring throughput/data distribution across partitions.
- 5.2Backup and restore
Understand choosing periodic vs continuous backup, configuring periodic backup, continuous backup and point-in-time restore (PITR), locating a restore point, and restoring a database/container.
- 5.3Security, data movement, and DevOps
Understand service-managed vs customer-managed keys (CMK), network access control, control-plane RBAC vs data-plane Entra ID, Key Vault, Always Encrypted, data movement (ADF/Spark/Kafka/Stream Analytics), and DevOps via ARM templates and PowerShell/CLI.