MuleSoft Certified Developer – Level 1 (Mule 4) DELTA Exam
Demonstrate your ability to work with Mule 4 APIs and integrations with the MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam.
About
Mule 4 DELTA Certification Exam – Summary
Show you can design, build, test, debug, deploy, and manage basic Mule 4 APIs and integrations with the MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam.
This certification is suitable for MuleSoft Certified Developers – Integration and API Associates (Mule 3.8+) who want to demonstrate their skills with Mule 4.

Approach
Certification Objectives
Take the MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam to show your knowledge of:
- using MuleSoft-hosted Anypoint Platform to take a basic API through all the steps of its lifecycle: design, build, deploy, manage, and govern
- using Anypoint Studio to build, test, and debug basic Mule 4 integrations and API implementations
- using Mule 4 connectors to connect to a range of resources including databases, files, web services, SaaS applications, and JMS queues
- performing basic data transformations using DataWeave 2
- using Mule 4 event processors to control event flow, handle errors, and process batch records

MuleSoft Certified Developer – Level 1 (Mule 4) DELTA Exam: Format
- format: multiple-choice, closed book, proctored online or in a testing centre
- length: 35 questions
- duration: 75 minutes
- pass score: 70 percent
- language: English
- the MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam can be taken a maximum of two times, with a 24-hour wait between attempt; after an unsuccessful second attempt, the candidate can only take the full MCD – Level 1 exam
Delivery Methods
You can choose to take the MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam in-person at a testing centre or online using a web camera, administered via the Kryterion Webassessor testing platform.
If you choose in-person at a Kryterion Testing Centre:
- over 1000 locations worldwide
- onsite instructions
- a test-taker guide
If you choose online using the Kryterion Webassessor testing platform:
- requires a webcam – a laptop webcam can be used, an external camera is not required
- requires internet connectivity with 1 Mbps upload, 1 Mbps download, jitter <50ms, ping <200ms
- use the tool to determine your internet speed and reliability
- online instructions
- a test-taker guide
If you think your connection might be unreliable, we recommend you choose a testing centre instead. An unreliable connection may cause you to be expelled from the exam.
Exam Preparation
- MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam takers can best prepare by taking the instructor-led Anypoint Platform Development: Mule 4 for Mule 3 Users course
- candidates should be familiar with all the course content and be able to apply it before taking the exam
Exam Topics
In the topics below, DEV:443 refers to the instructor-led version of the Anypoint Platform Development: Mule 4 for Mule 3 Users course, while DEV:DIY4 refers to the MCD – Level 1 / Development Fundamentals (Mule 4) Self-Assessment Quiz & DIY Exercises materials.
The MuleSoft Certified Developer – Level 1 (Mule 4) DELTA exam demonstrates proficiency in the following tasks:
Accessing and Modifying Mule Events
- describe the Mule event data structure
- use transformers to set event payloads, attributes, and variables
- write DataWeave expressions to access and modify event payloads, attributes, and variables
- enrich Mule events using target parameters
- DEV:443 Module 1
- DEV:DIY4 Exercise 6-1, 7-1, and 7-2
- about Mule Event
- set Payload
- set Variable
- about the Transform Component
- about DataWeave
- Logger Component Example
- Enriching Data with Target Parameters
Structuring Mule Applications
- parameterise an application using property placeholders
- define and reuse global configurations in an application
- break an application into multiple flows using private flows, subflows, and the Flow Reference component
- specify what data (payload, attributes, variables) is persisted between flows when a Flow Reference is used
- specify what data is persisted between flows when a Mule event crosses a connection boundary
- specify what data exists in a flow before and after a call in the middle of a flow to an external resource
- DEV:443 Module 1
- DEV:443 Module 2
- DEV:DIY4 Exercise 7-1 and 7-2
- To Configure Property Placeholders for Mule Apps
- Global Elements
- Flow and Subflow Components
- About Flow Ref
Building API Implementation Interfaces
- manually create a RESTful interface for a Mule application
- generate a REST Connector from a RAML specification
- describe the features and benefits of APIkit
- use APIkit to create implementation flows from a RAML file
- describe how requests are routed through flows generated by APIkit
- DEV:DIY4 Exercise 4-1
- Converting a RAML to a Connector Using REST Connect
- Workflow: Creating Testing, and Implementing an API
- HTTP Request Configuration Reference: Adding Custom Parameters
Routing Events
- use the Choice router to route events based on conditional logic
- use the Scatter-Gather router to multicast events
- validate data using the Validation module
- DEV:443 Module 4
- DEV:DIY4 Exercise 9-1
- Choice Router
- DataWeave Operators
- Flow Control in DataWeave
- About Scatter-Gather
- Validation Module
Handling Errors
- describe the default error handling in a Mule application
- define a custom global default error handler for an application and identify in what situations it will be used
- compare and contrast how the On Error Continue and On Error Propagate scopes work
- create one or more error handlers for a flow
- use the Try scope to specify error handlers for one or more event processors
- describe the data structure of the Mule Error object
- map errors to custom application errors
- DEV:443 Module 5
- DEV:DIY4 Exercise 10-1
- Introduction to Mule 4: Error Handlers
- About Error Handling
- About On-Error Scopes
- Try Scope
- About the Mule Error
- Introduction to Mule 4: Error Mapping
Transforming Data with DataWeave
- write DataWeave scripts to convert JSON, XML, and Java data structures to different data structures and data types
- use DataWeave functions
- define and use DataWeave variables, functions, and modules
- define and use custom data types
- apply correct DataWeave syntax to coerce data types
- apply correct DataWeave syntax to format strings, numbers, and dates
- call Mule flows from a DataWeave script
- DEV:443 Module 6
- DEV:DIY4 Exercise 11-1
- Data Formats Supported by DataWeave
- Defining DataWeave Functions
- Creating Custom Modules and Mappings
- About DataWeave Variables
- Using lookup To Call External Flows
- About Type Coercion with DataWeave
Using Connectors
- retrieve data from a Database using the Database connector
- create parameterized SQL queries for the Database connector
- retrieve data from a REST service using the HTTP Request operation or a REST Connector
- use a Web Service Consumer connector to consume a SOAP web service
- use the Transform Message component to pass arguments to a SOAP web service
- list, read, and write local files using the File connector
- list, read, and write remote files using the FTP connector
- use the JMS connector to publish and listen for JMS messages
- DEV:443 Module 1
- DEV:443 Module 3
- DEV:443 Module 7
- DEV:DIY4 Exercise 4-1, 8-1, 12-1, and 12-2
- Database Connector
- About the File Connector
- About the FTP Connector
- About the JMS Connector
Processing Records
- list and compare and contrast the methods for processing individual records in a collection
- explain how Mule events are processed by the For Each scope
- use the For Each scope to process records
- explain how Mule events are processed by the Batch Job scope
- use a Batch Job with Batch Steps and a Batch Aggregator to process records
- use the Scheduler component to trigger a flow
- use connector listeners to trigger flows
- describe the features, benefits, and process to use automatic watermarking vs. manual watermarking
- use connectors with automatic watermarking capabilities
- persist data between flow executions using the Object Store
- DEV:443 Module 7
- DEV:DIY4 Exercise 13-1
- For Each Scope
- About Batch Job
- Scheduler Endpoint (Trigger)
- To Trigger a Flow When a New File is Created or Modified
- Database Connector Documentation Reference: On Table Row Listener
- Object Store Connector
Debugging and Troubleshooting Mule Applications
- use breakpoints to inspect a Mule event during runtime
- install missing Maven dependencies
- read and decipher Mule log error messages
- DEV:DIY4 Exercise 6-1 and Walkthrough
- DEV:DIY4 all exercises
Deploying and Managing APIs and Integrations
- package Mule applications for deployment
- deploy applications to CloudHub
- use CloudHub properties to ensure deployment success
- create and deploy API proxies
- connect an API implementation to API Manager using autodiscovery
- use policies, including client ID enforcement, to secure an API
- create SLA tiers and apply SLA based policies
- DEV:DIY4 Exercise 5-1 and 5-2
- Deploying to CloudHub
- Configuring API Autodiscovery in a Mule 4 Application
- About Policies
- To Apply a Policy and SLA Tier
About Influential Software
The Influential Software team has been delivering quality business software, services, and training for over 25 years. As a certified MuleSoft Partner, we are experts in data integration and the key technologies used in MuleSoft Anypoint Platform.
Our UK teams work on- and off-site for enterprises of all sizes, from FTSE 100/250 companies to SMEs. The result is hundreds of successful projects and long-term client partnerships.

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