SF-PD2 Practice Test 10 — 10 Questions

Question 1

A developer is creating a REST API endpoint in Salesforce that external systems will call to create Case records. The external system sends a JSON payload with a custom header 'X-API-Key' for authentication. The developer needs to validate this key against a custom setting before processing the request. Which Apex class should the developer use to implement this endpoint?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

A class annotated with @RestResource(urlMapping='/Cases/*'). The correct approach is to use a class annotated with @RestResource and a URL mapping. This exposes the Apex class as a REST endpoint. The developer can then define a method with @HttpPost to handle incoming POST requests, validate the 'X-API-Key' header against a custom setting, and create Case records. Other interfaces like Schedulable, Batchable, or Queueable are for asynchronous processing and do not provide REST endpoints.

Answer

A class that implements the Queueable interface

Answer

A class that implements the Schedulable interface

Answer

A class that implements the Database.Batchable interface

Question 2

A developer is building a Lightning Web Component for a Lightning Experience record page. The component must display a toast notification to the user after a successful save operation. The developer uses the ShowToastEvent from the lightning/platformShowToastEvent module. Which import statement is correct?

Accepted Answer

import { ShowToastEvent } from 'lightning/platformShowToastEvent';. The correct import statement is the one that uses the exact module name 'lightning/platformShowToastEvent' and the named export ShowToastEvent. This is the only valid way to import the toast event class in LWC. After importing, the developer instantiates the event with new ShowToastEvent({...}) and dispatches it. The other options either use wrong export names, wrong import styles, or incorrect module paths, all of which would fail at build time.

Answer

import { showToast } from 'lightning/platformShowToastEvent';

Answer

import ShowToastEvent from 'lightning/platformShowToastEvent';

Answer

import { ShowToastEvent } from 'lightning/toastEvent';

Question 3

A developer must write Apex tests that reliably cover a Queueable class which performs a callout and then enqueues a second Queueable job. The tests must not make real external callouts. (Choose two.)

Accepted Answer

Implement HttpCalloutMock and register it with Test.setMock(HttpCalloutMock.class, mock) before invoking the Queueable.. To test a Queueable that makes a callout and chains another job without real external calls, the developer registers an HttpCalloutMock so the callout is stubbed, and wraps the enqueue in Test.startTest()/Test.stopTest() so queued work runs synchronously. Together these techniques validate both the callout handling and the chained job's behavior in a controlled, offline test.

Answer

Annotate the test method with @IsTest(SeeAllData=true) so the chained job can see the records it needs.

Answer

Set the Queueable to run with System.enqueueJob(new MyQueueable(), 5) to increase the delay so the test can observe intermediate state.

Answer

Replace the callout with a hard-coded response inside the Queueable when Test.isRunningTest() returns true.

Question 4

A developer is integrating Salesforce with an external ERP using a REST API. The ERP requires that each request include a unique correlation ID for tracing. The developer implements an Apex callout that sends the correlation ID in a custom HTTP header. During testing, the callout succeeds, but the ERP logs show that the correlation ID is missing. What is the most likely cause?

Accepted Answer

The HTTP request was created using a new HttpRequest() object, but the header was set on a different HttpRequest instance.. The correct answer is that the header was set on a different HttpRequest instance than the one sent. In Apex, HttpRequest objects are not immutable; you must set headers on the same object that you pass to Http.send(). If two instances are created, the header on the unused instance is ignored, leading to the external system not receiving it. This is a subtle but common coding error.

Answer

The header name must be prefixed with 'X-' to be recognized by the external system.

Answer

The custom header was added to the request after the callout was sent.

Answer

Salesforce automatically strips custom headers from outbound callouts for security reasons.

Question 5

A developer is troubleshooting a production issue where a trigger occasionally exceeds CPU time limits. The developer wants to capture detailed debug logs for a specific user without slowing down the entire org, and then analyze the log to identify the slowest operations. Which combination of Salesforce tools should the developer use?

Accepted Answer

Debug Logs with a user-specific trace flag, then the Analysis perspective in the Developer Console. A user-specific trace flag generates debug logs only for that user, keeping overhead contained while capturing the problematic transaction. The Developer Console's Analysis perspective then parses the log and ranks operations by execution time, exposing the slowest SOQL, DML, and method calls. This focused capture and analysis directly targets the CPU time issue without impacting other users.

Answer

Event Monitoring via the EventLogFile object, then Workbench to query the logs

Answer

Setup Audit Trail to identify the user, then Apex Replay Debugger to step through the log

Answer

Apex Profiler in VS Code with the Apex extension, then the Timeline view

Question 6

A developer is writing a test class for a service that performs a callout to an external web service. The developer needs to mock the callout response to test different scenarios without making actual HTTP requests. Which interface should the developer implement to mock the callout?

Accepted Answer

HttpCalloutMock. The HttpCalloutMock interface is the correct choice for mocking HTTP callouts in Apex tests. It allows developers to define custom responses for callouts, enabling comprehensive testing without external dependencies. WebServiceMock is for SOAP services, Database.AllowsCallouts is for enabling callouts in asynchronous Apex, and System.HttpMock is not a valid interface.

Answer

Database.AllowsCallouts

Answer

WebServiceMock

Answer

System.HttpMock

Question 7

A developer is optimizing an Apex class that performs a large number of DML operations. The class currently updates records one at a time in a loop. Which two techniques should be used to improve performance? (Choose two.)

Accepted Answer

Use a Map to deduplicate records before performing DML.. The two key techniques are bulkifying DML by collecting records into a list and performing a single DML call, and using a Map to deduplicate records to avoid redundant operations. These reduce the number of DML statements and ensure efficient processing within governor limits. The other options do not address the core inefficiency of per-record DML.

Answer

Use Database.update with the allOrNone parameter set to false.

Answer

Use the insert method instead of update to avoid conflicts.

Answer

Use the @future annotation to perform DML asynchronously.

Question 8

A developer is building a Lightning Web Component that displays a list of Accounts with their related Contacts. The component currently performs a separate SOQL query for each Account to retrieve its Contacts, resulting in 200 queries when 200 Accounts are displayed. The developer wants to reduce the number of queries to improve performance and avoid hitting governor limits. Which approach should be used?

Accepted Answer

Use a single SOQL query with a subquery to retrieve Accounts and their related Contacts.. Using a single SOQL query with a subquery retrieves both parent and child records in one call, eliminating the N+1 query problem. This approach is efficient, respects governor limits, and is the recommended pattern for displaying related records in Lightning Web Components. It ensures that only the necessary data is retrieved and reduces round trips to the database.

Answer

Use a SOQL query to retrieve all Contacts and then use Apex to group them by AccountId.

Answer

Use a separate SOQL query for each Account but cache the results in Platform Cache to reduce database calls.

Answer

Use Database.query with a bind variable to retrieve all Accounts and then use a Map to associate Contacts.

Question 9

A developer is building an Apex controller for a Visualforce page that must display a list of 2,000 Contacts for an Account. The current implementation uses a SOQL query inside a loop to fetch Contacts for each Account row, resulting in sluggish page loads and occasional governor limit errors. Which approach should the developer take to improve performance?

Accepted Answer

Move the SOQL query outside the loop and use a Map to correlate Contacts to Accounts.. The correct approach is to bulkify the code by moving the SOQL query outside the loop and using a Map to correlate child records to parents. This reduces the number of queries to one, avoiding governor limits and improving performance. The other options either do not eliminate the loop query or introduce inappropriate tools.

Answer

Add a LIMIT clause to the SOQL query inside the loop to reduce the number of records returned per Account.

Answer

Use Database.getQueryLocator to handle the Contacts and bind the result to the page.

Answer

Replace the SOQL query with a SOSL search to retrieve all Contacts at once.

Question 10

A developer is designing a solution to calculate real-time statistics on a high-volume custom object, `Sensor_Reading__c`, which receives thousands of new records per hour. The statistics must be displayed on a Lightning Web Component (LWC) dashboard and must reflect the most recent data within 5 minutes. The developer considers using a scheduled Apex job to aggregate data every 5 minutes, but the aggregation query takes longer than 5 minutes to run. What is the most appropriate approach to meet the performance requirement?

Accepted Answer

Implement a Change Data Capture (CDC) event subscriber that updates a custom summary object in real time as new Sensor_Reading__c records are inserted.. Change Data Capture (CDC) allows real-time streaming of record changes. By subscribing to CDC events for `Sensor_Reading__c`, the developer can incrementally update a summary object as each new reading is inserted, avoiding the need for a long-running aggregation query. This meets the 5-minute freshness requirement and scales with high volume. Other options either rely on slow batch processing or incorrect use of formula fields.

Answer

Create a formula field on Sensor_Reading__c that calculates the statistics dynamically and reference it in the LWC.

Answer

Use a Platform Cache to store the aggregated statistics and refresh it asynchronously using a Queueable job triggered by a record-triggered flow.

Answer

Use a Batch Apex job with a scope size of 1 to process each new record individually and update the summary object.