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DP-420

Azure Cosmos DB Developer
Specialty

The specialty certification for Azure Cosmos DB developers. Design data models, write efficient queries, implement global distribution, and optimize performance — explained with real code examples and production scenarios.

📖

Study Guide

28 interactive modules

All 11 Domain 1 modules (Design and Implement Data Models — the biggest domain at 35-40%) + 11 practice questions. No account needed.

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✍️

Practice Exam

200 exam-style questions

Study mode with explanations + timed exam simulation. 11 free questions.

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28

Modules

200

Questions

5

Domains

Free

Domain 1 included

📝 Sample Question

A multi-tenant SaaS application uses /tenantId as the partition key. Five enterprise tenants each store 25 GB of data. Users report write failures (HTTP 429) only for these tenants. What is the MOST likely cause?

A. The Cosmos DB account has reached its storage limit
B. The enterprise tenants exceed the 20 GB logical partition size limit ✓
C. The container needs more provisioned throughput (RU/s)

📊 What you'll cover

Design and Implement Data Models (Free) 11 modules
Design and Implement Data Distribution 3 modules
Integrate and Move Data 3 modules
Optimize Query and Operation Performance 4 modules
Maintain an Azure Cosmos DB Solution 7 modules

What you'll learn

🗄️

Data Models & Partition Keys

Access-pattern-driven design, embedding vs referencing, synthetic and hierarchical partition keys, and the 20 GB logical partition limit.

🌍

Global Distribution

Five consistency levels (strong to eventual), multi-region writes, conflict resolution, and failover strategies.

💻

SDK & Server-Side Code

C# and Java CRUD operations, transactional batches, SQL queries, LINQ, stored procedures, triggers, and UDFs.

⚡

Performance & Cost

Indexing policies, Request Unit optimization, integrated cache, serverless vs provisioned vs autoscale throughput.

Full Curriculum

28 interactive modules across 5 exam domains

1

Design and Implement Data Models

11 modules

Free

The exam's biggest domain (35-40%). Data modelling, partition key strategy, embedding vs referencing, SDK operations, SQL queries, LINQ, stored procedures, triggers, and transactional batches — with real C# and Java code.

  1. 1Cosmos DB: The Big Picture
  2. 2Design a Non-Relational Data Model
  3. 3Partition Key Strategy for Read and Write Workloads
  4. 4Synthetic and Hierarchical Partition Keys
  5. 5Relationships: Embedding, Referencing, and Change Feed
  6. 6Connect to Cosmos DB with the SDK
  7. 7CRUD and Transactional Batch Operations
  8. 8SQL Queries for Cosmos DB
  9. 9SDK Query Operations: LINQ, Pagination, and Continuations
  10. 10Stored Procedures, UDFs, and Triggers
  11. 11Multi-Item Transactions in Practice
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2

Design and Implement Data Distribution

3 modules

Premium

Global replication, automatic and manual failover, the five consistency levels (strong through eventual), multi-region writes, and conflict resolution — the distributed systems heart of Cosmos DB.

  1. 1Global Replication and Failover
  2. 2Consistency Levels: Five Choices, Real Trade-Offs
  3. 3Multi-Region Writes and Conflict Resolution
Preview Domain
3

Integrate and Move Data

3 modules

Premium

Change feed with Azure Functions and the Change Feed Processor, analytical workloads with Synapse Link and Fabric mirroring, and data movement strategies using ADF, Kafka, and Spark connectors.

  1. 1Change Feed with Azure Functions and Processors
  2. 2Analytical Workloads: Synapse Link and Fabric Mirroring
  3. 3Data Movement: ADF, Kafka, and Spark Connectors
Preview Domain
4

Optimize Query and Operation Performance

4 modules

Premium

Indexing policies (range, spatial, composite), Request Unit calculation and optimization, the integrated cache with dedicated gateway, and change feed patterns for materialized views and event-driven architecture.

  1. 1Indexing Policies: Range, Spatial, and Composite
  2. 2Request Units and Query Cost Optimization
  3. 3Integrated Cache and Dedicated Gateway
  4. 4Change Feed Patterns: Materialized Views and Estimator
Preview Domain
5

Maintain an Azure Cosmos DB Solution

7 modules

Premium

Monitoring with Azure Monitor, backup and restore (periodic vs continuous), network security, data encryption and RBAC, cost optimization across throughput modes, Infrastructure as Code with Bicep and CLI, and exam preparation.

  1. 1Monitoring: Metrics, Logs, and Alerts
  2. 2Backup and Restore: Periodic vs Continuous
  3. 3Network Security: Firewalls, VNets, and Private Endpoints
  4. 4Data Security: Encryption, Keys, and RBAC
  5. 5Cost Optimization: Throughput Modes and RU Strategy
  6. 6DevOps: Infrastructure as Code and Deployments
  7. 7Exam Strategy and Cross-Domain Review
Preview Domain

Practice Exam Lab

200 original questions — two study modes

📖

Study Mode

Learn as you go

  • ✓ See explanation after each question
  • ✓ "Why wrong" for every option
  • ✓ Real-world context & exam tips
  • ✓ Microsoft Learn links
⏱️

Exam Mode

Simulate the real thing

  • ✓ 120 minutes timed session
  • ✓ Randomised question order
  • ✓ Score breakdown by domain
  • ✓ Pass/fail against 700 / 1000
1

Design and Implement Data Models

80 questions · Exam weight: 35-40%

11 Free

20

Easy

40

Medium

20

Hard

Every question includes a scenario, detailed explanation, and a link to Microsoft Learn.

Try Free Questions →
2

Design and Implement Data Distribution

20 questions · Exam weight: 5-10%

0 Free

5

Easy

10

Medium

5

Hard

Every question includes a scenario, detailed explanation, and a link to Microsoft Learn.

Preview Questions
3

Integrate and Move Data

20 questions · Exam weight: 5-10%

0 Free

5

Easy

10

Medium

5

Hard

Every question includes a scenario, detailed explanation, and a link to Microsoft Learn.

Preview Questions
4

Optimize Query and Operation Performance

40 questions · Exam weight: 15-20%

0 Free

10

Easy

20

Medium

10

Hard

Every question includes a scenario, detailed explanation, and a link to Microsoft Learn.

Preview Questions
5

Maintain an Azure Cosmos DB Solution

40 questions · Exam weight: 25-30%

0 Free

10

Easy

20

Medium

10

Hard

Every question includes a scenario, detailed explanation, and a link to Microsoft Learn.

Preview Questions

🎁 Free tier: 11 questions. No account needed.

Choose your path

Start free. Upgrade when you're ready.

Practice Exam

$14

one-time purchase

  • ✓ 200 exam-style questions
  • ✓ Study mode + Exam mode
  • ✓ Detailed explanations

Study Guide

$19

one-time purchase

  • ✓ 28 interactive modules
  • ✓ Flashcards & ELI5
  • ✓ Progress tracking
Recommended

Complete Bundle

$29

save $4

  • ✓ Everything in both
  • ★ Best value

🎁 Free tier: All 11 Domain 1 modules (Design and Implement Data Models — the biggest domain at 35-40%) + 11 practice questions. No account needed. No account needed.

About the DP-420 Exam

Exam code
DP-420
Duration
120 minutes
Passing score
700 / 1000
Question types
MCQ, multi-select, case studies, drag-and-drop
Cost
$165 USD

Exam Domains & Weights

D1: Design and Implement Data Models (35-40%)
D2: Design and Implement Data Distribution (5-10%)
D3: Integrate and Move Data (5-10%)
D4: Optimize Query and Operation Performance (15-20%)
D5: Maintain an Azure Cosmos DB Solution (25-30%)
View on Microsoft Learn →

Frequently Asked Questions

What is DP-420?
DP-420 is the Microsoft Azure Cosmos DB Developer Specialty certification. It validates your ability to design data models, write efficient queries, implement global distribution, and maintain Cosmos DB solutions at scale.
Is DP-420 hard?
DP-420 is a specialty-level exam focused entirely on Cosmos DB. Partition key selection and consistency levels are the two topics that trip up most candidates. The exam expects you to read and understand C# and Java code.
What prerequisites do I need?
Microsoft recommends solid knowledge of Azure, application development (C#, Java, or JavaScript), and NoSQL database concepts. Experience with Azure Cosmos DB is strongly recommended.
Does this course include code examples?
Yes — every SDK and query concept includes working C# and Java code with line-by-line explanations. This is a developer specialty cert, and code is essential.
What is included in the free tier?
All 11 Domain 1 modules (Design and Implement Data Models — the biggest domain at 35-40%) plus practice questions. No account needed.
Is this a one-time purchase?
Yes. Pay once, access forever. No recurring fees.

Ready to start?

Try the free tier. Upgrade when you're ready to pass.

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