Top 30 D365 CRM Developer Interview Questions to Master JavaScript Plugins and Azure Integration

As a Microsoft Dynamics 365 CRM Developer with over three years of experience, you’re expected to have a strong grasp of core CRM functionalities, customizations, plugins, workflows, Power Platform integrations, and deployment strategies. Below is a curated list of interview questions and answers to help you prepare effectively.

Section 1: JavaScript in D365 CRM

1. How do you retrieve the value of a field using JavaScript?

Answer:
Use the formContext to access the field value:

var formContext = executionContext.getFormContext();
var name = formContext.getAttribute("name").getValue();

Note: Always retrieve formContext from the executionContext to ensure compatibility.

2. How do you set a field value using JavaScript?

Answer:
Set the value using setValue:

var formContext = executionContext.getFormContext();
formContext.getAttribute("name").setValue("New Value");

Note: Ensure the field exists and is editable to avoid errors.

3. How do you hide or show a field on a form?

Answer:
Control visibility with setVisible:

var formContext = executionContext.getFormContext();
formContext.getControl("name").setVisible(false); // Hide
formContext.getControl("name").setVisible(true);  // Show

Note: Verify the control exists to prevent runtime errors.

4. How do you disable a field using JavaScript?

Answer:
Disable a field using setDisabled:

var formContext = executionContext.getFormContext();
formContext.getControl("name").setDisabled(true);  // Disable
formContext.getControl("name").setDisabled(false); // Enable

5. How do you handle the form load event in D365?

Answer:
Register a function on the form’s OnLoad event:

function onLoad(executionContext) {
    var formContext = executionContext.getFormContext();
    // Add logic here, e.g., set field visibility or default values
}

Note: Add the function to the form’s event handler in the form properties and pass the execution context.

6. How can you retrieve the lookup field value?

Answer:
Access lookup field details as an array:

var formContext = executionContext.getFormContext();
var lookup = formContext.getAttribute("parentcustomerid").getValue();
if (lookup && lookup.length > 0) {
    var id = lookup[0].id;           // GUID
    var name = lookup[0].name;       // Display name
    var entityType = lookup[0].entityType; // Entity logical name
}

Note: Check for null or empty arrays to avoid errors.

7. How do you call a Web API to retrieve a record using JavaScript?

Answer:
Use Xrm.WebApi for secure API calls:

var formContext = executionContext.getFormContext();
var accountId = formContext.data.entity.getId().replace(/[{}]/g, "");
Xrm.WebApi.retrieveRecord("account", accountId, "?$select=name,accountnumber").then(
    function success(result) {
        console.log("Account Name: " + result.name);
    },
    function (error) {
        console.error("Error: " + error.message);
    }
);

Note: Specify required fields in the $select query to optimize performance.

8. How do you validate required fields using JavaScript?

Answer:
Check for empty values and display a notification:

var formContext = executionContext.getFormContext();
if (!formContext.getAttribute("name").getValue()) {
    formContext.ui.setFormNotification("Name is required.", "ERROR", "nameValidation");
    formContext.getAttribute("name").setRequiredLevel("required");
}

Note: Use unique notification IDs and clear notifications with clearFormNotification when resolved.

9. How do you get the form type in D365?

Answer:
Retrieve the form type to determine the form’s state:

var formContext = executionContext.getFormContext();
var formType = formContext.ui.getFormType(); // 1 = Create, 2 = Update, 3 = Read Only, 4 = Disabled

Note: Use form type to apply conditional logic (e.g., disable fields on read-only forms).

10. How do you dynamically add an option to an option set field?

Answer:
Add a new option to an option set control:

var formContext = executionContext.getFormContext();
formContext.getControl("statuscode").addOption({
    text: "New Option",
    value: 100000001 // Use a unique integer not already in use
});

Note: Ensure the value is unique and within the allowed range for the option set.

Section 2: Plugins in D365 CRM

1. What is a plugin in D365, and where does it execute?

Answer:
A plugin is a custom C# class that extends D365’s core functionality by executing server-side logic in response to events like Create, Update, or Delete. Plugins run on the Dynamics 365 server, either online (in a sandbox) or on-premises (full trust).

2. What are the plugin pipeline stages?

Answer:
The plugin execution pipeline has three stages:

• Pre-Validation: Before security checks, outside the transaction.
• Pre-Operation: After validation, before the database operation, within the transaction.
• Post-Operation: After the database operation, within the transaction.

Note: Choose the stage based on whether you need to modify data before or after the core operation.

3. How do you retrieve the target entity in a plugin?

Answer:
Access the target entity from the plugin context:

public void Execute(IServiceProvider serviceProvider)
{
    var context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
    if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
    {
        Entity target = (Entity)context.InputParameters["Target"];
        // Access attributes, e.g., string name = target.GetAttributeValue<string>("name");
    }
}

Note: Verify the target exists to avoid null reference errors.

4. What are PreEntityImages and PostEntityImages used for?

Answer:

• PreEntityImages: Contain attribute values before the operation (e.g., for Update/Delete).
• PostEntityImages: Contain attribute values after the operation.
  Used to compare old and new values or retrieve unchanged attributes.

Example:

Entity preImage = context.PreEntityImages["PreImage"];
string oldName = preImage.GetAttributeValue<string>("name");

Note: Images must be registered in the plugin step.

5. How do you create a plugin step for an update on an account?

Answer:
In the Plugin Registration Tool:

1. Register the plugin assembly.
2. Create a step with:
   • Message: Update
   • Primary Entity: account
   • Stage: Pre-Operation or Post-Operation
   • Execution Mode: Synchronous or Asynchronous
3. Optionally, add filtering attributes to trigger only on specific field changes.

Note: Test the step in a non-production environment first.

6. What is the difference between synchronous and asynchronous plugins?

Answer:

• Synchronous: Executes immediately, blocking the user until completion. Used for critical validations.
• Asynchronous: Runs in the background, not blocking the user. Used for non-critical, time-consuming tasks.

Note: Asynchronous plugins improve user experience but may delay data updates.

7. How do you throw a business error in a plugin?

Answer:
Throw an InvalidPluginExecutionException to display an error to the user:

throw new InvalidPluginExecutionException("Validation failed: Name cannot be empty.");

Note: Provide clear, user-friendly error messages.

8. How do you perform CRUD operations in a plugin?

Answer:
Use the IOrganizationService to perform Create, Update, Retrieve, or Delete operations:

var service = (IOrganizationService)serviceProvider.GetService(typeof(IOrganizationService));
Entity account = new Entity("account") { ["name"] = "New Account" };
Guid accountId = service.Create(account);

// Update
account["name"] = "Updated Account";
service.Update(account);

Note: Ensure proper error handling using try-catch blocks.

9. How do you debug a plugin in an online environment?

Answer:

1. Install the Plugin Profiler in the Plugin Registration Tool.
2. Reproduce the scenario to capture a log.
3. Download the log file and attach it in Visual Studio.
4. Set breakpoints and replay the plugin execution.

Note: Enable tracing in D365 to capture additional details if needed.

10. What is the difference between Shared and Isolated mode in plugin registration?

Answer:

• Isolated (Sandbox): Runs in a restricted environment with limited access (mandatory for D365 Online).
• Shared (None): Full trust mode with unrestricted access (only for on-premises).

Note: Sandbox mode limits external connections and file system access.

Section 3: Azure Integration with D365

1. What Azure services have you integrated with D365 CRM?

Answer:
Common services include:

• Azure Functions: For serverless logic execution.
• Azure Logic Apps: For workflow automation.
• Azure Service Bus: For asynchronous messaging.
• Azure Blob Storage: For file storage.
• Azure Key Vault: For secure secret management.
• Azure API Management: For exposing secure APIs.

2. How does Azure Service Bus integrate with D365 CRM?

Answer:

1. Register a service endpoint in the Plugin Registration Tool.
2. Configure a plugin step to send messages to the Service Bus queue or topic.
3. An Azure Function, Logic App, or other consumer processes the messages.

Example: A plugin triggers a message on account creation, and an Azure Function updates an external system.

Note: Use SAS or AAD authentication for secure communication.

3. Describe a scenario where you used Azure Functions in D365.

Answer:
Scenario: When an account is created in D365, a plugin triggers an Azure Function to validate the account’s tax ID via a third-party API. The function returns the result, and a Logic App updates a custom field in D365.

Implementation:

• Plugin sends account data to an Azure Service Bus queue.
• Azure Function processes the queue message and calls the API.
• Logic App updates D365 using the Dataverse connector.

4. What authentication methods are used for secure integration with Azure?

Answer:

• OAuth 2.0: For token-based authentication with Azure AD.
• Azure AD App Registration: Uses Client ID/Secret or certificates.
• Managed Identity: For secure, passwordless access between Azure services.

Note: Store secrets in Azure Key Vault for enhanced security.

5. What are the benefits of using Logic Apps over Power Automate?

Answer:

• Advanced Error Handling: Logic Apps offer detailed retry policies and error workflows.
• Scalability: Better suited for enterprise-scale integrations.
• Developer Tools: Supports code view, ARM templates, and Visual Studio integration.
• Custom Connectors: Easier to create and manage custom APIs.

Note: Power Automate is more user-friendly for non-developers.

6. How do you handle failures in Azure-integrated processes?

Answer:

• Retries: Configure retry policies in Azure Functions or Logic Apps.
• Logging: Use Azure Application Insights for monitoring and diagnostics.
• Alerts: Set up notifications via Logic Apps or Azure Monitor.
• Fallbacks: Implement durable functions for complex workflows with state management.

Note: Test failure scenarios to ensure robustness.

7. How can you upload large files from D365 to Azure Blob Storage?

Answer:

1. Create a custom plugin or Power Automate flow to extract the file (e.g., from a note attachment).
2. Use an Azure Function or Logic App to upload the file to Blob Storage via the Azure Blob Storage connector or SDK.
3. Store the Blob URL in a D365 field for reference.

Example:

// Plugin code to extract file
Entity note = service.Retrieve("annotation", noteId, new ColumnSet("documentbody"));
string fileContent = note.GetAttributeValue<string>("documentbody");
// Send to Azure Function via Service Bus

Note: Handle large files in chunks to avoid memory issues.

8. How does throttling affect Azure-D365 integration, and how do you handle it?

Answer:
Throttling occurs when API limits (e.g., Dataverse or Azure) are exceeded, causing delays or errors.

Handling:

• Retry Policies: Implement exponential backoff in Azure Functions or Logic Apps.
• Batch Operations: Use bulk APIs to reduce the number of calls.
• Monitoring: Track API usage with Application Insights.
• Optimization: Cache results or use delta queries where possible.

Note: Review Microsoft’s throttling limits for Dataverse.

9. How do you secure APIs exposed by Azure Functions?

Answer:

• Azure AD Authentication: Require OAuth tokens for access.
• API Keys: Use function-level or host-level keys.
• IP Restrictions: Configure allowed IP ranges in Azure.
• CORS: Restrict cross-origin requests to trusted domains.

Note: Regularly rotate keys and monitor access logs.

10. Can D365 call Azure Functions directly from JavaScript?

Answer:
Yes, using fetch or XMLHttpRequest, with proper authentication and CORS configuration:

var formContext = executionContext.getFormContext();
var data = { id: formContext.data.entity.getId() };
fetch("https://yourfunction.azurewebsites.net/api/yourFunc?code=yourApiKey", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(data)
})
.then(response => response.json())
.then(result => console.log(result))
.catch(error => console.error(error));

Note: Use Azure AD tokens instead of API keys for better security in production.

Wrap-Up Tips

• Share Real Examples: Talk about projects you’ve worked on to show your skills.
• Practice Coding: Be ready to write JavaScript code or fix plugin issues during the interview.
• Focus on Cloud: Highlight your Azure skills, as D365 relies heavily on cloud tools.
• Documentation: Refer to Microsoft’s official documentation for Web API, plugins, and Azure integrations during preparation.