SF-PD2 Hard Questions — 25 Difficult Questions

Question 1

A developer is writing an Apex trigger that should only fire when specific fields are changed. Which THREE practices help optimize the trigger's performance?

Accepted Answer

Check field values in the trigger to avoid redundant logic.. Trigger optimization is essential for preventing unnecessary processing. By checking if fields have actually changed, the developer avoids executing logic when no relevant data updates have occurred. Furthermore, decoupling logic into service classes keeps the trigger thin and manageable, while early-exit patterns ensure the code finishes as fast as possible if conditions aren't met, maintaining high system throughput and preventing governor limit issues.

Answer

Perform all DML operations inside the trigger loop.

Answer

Execute all SOQL queries for every record in the trigger.

Question 2

Refer to the exhibit. What is the primary security advantage of using a 'Named Credential' in this callout as opposed to hardcoding the API endpoint and credentials?

Accepted Answer

It centralizes credential management and prevents hardcoded secrets.. Named Credentials encapsulate the authentication process and the endpoint URL, separating the integration configuration from the source code. This not only makes the code cleaner but also provides centralized management of sensitive credentials. If credentials expire or the endpoint changes, the developer updates the Named Credential object, and all associated integrations are updated simultaneously without requiring a deployment or code change.

Answer

It automatically encrypts the payload for transit.

Answer

It allows the code to bypass the 'Remote Site Settings' check.

Answer

It enables the use of custom HTTP verbs like PATCH or DELETE.

Question 3

A developer is writing a complex asynchronous batch Apex job that processes millions of financial transaction records. The job needs to maintain running totals across batches and update a summary logging record upon completion. Which mechanism allows state to be accurately preserved across individual executeBatch transactions?

Accepted Answer

Implement the Database.Stateful interface on the batch class definition to preserve instance member variable states across transaction chunks.. Implementing the Database.Stateful interface in a Batch Apex class ensures that instance member variables retain their values across distinct transaction chunks. Without this interface, member variables reset between execute method invocations. Preserving state is essential for maintaining running totals and aggregate metrics during large-scale data processing.

Answer

Declare instance member variables inside the batch class without implementing any special interfaces.

Answer

Store running totals inside static variables within the batch class, relying on the Apex transaction cache.

Answer

Write running totals to a custom metadata type record inside each execute method iteration.

Question 4

Refer to the exhibit. The Apex transaction is consistently hitting the CPU limit. What is the most likely cause and the best way to optimize the code?

Accepted Answer

Replace nested loops with Map-based lookups.. The CPU time limit is reached when the Apex code performs too many calculations, loops, or complex logic within a single transaction. Optimization requires reducing the complexity of the code, such as moving away from nested loops, using maps for faster lookups, or offloading heavy computations to asynchronous processes like Batch Apex or Queueable Apex. This ensures that the transaction completes within the time limit allocated by the platform.

Answer

Reduce the batch size in the Batch Apex class.

Answer

Increase the CPU limit in the organization configuration.

Answer

Use the 'transient' keyword for all variables.

Question 5

A company requires that an integration log all outbound API requests for auditing purposes, including the full request and response body. Given the potential for high volumes, which implementation is most efficient and compliant?

Accepted Answer

Use Platform Events to log the data asynchronously in a separate transaction.. Using a Platform Event to log integration data is the most efficient pattern. Because the logging happens asynchronously, it doesn't block the main business transaction. By publishing an event, a separate subscriber can handle the heavy lifting of storing the log in a custom object, ensuring the primary business operation remains performant while maintaining an audit trail for all outbound communications.

Answer

Insert a record into a custom 'Log' object synchronously within the integration class.

Answer

Store the logs in a static variable and write to the database at the end of the day.

Answer

Write the logs to the Debug Log and parse them later using a log monitoring tool.

Question 6

A developer is troubleshooting an Apex class that intermittently exceeds CPU time limits in production. The class performs complex string manipulation and recursive processing on large collections. The developer wants to capture detailed timing and query information for a specific user's transaction without enabling verbose logging for the whole org. Which tool should the developer use?

Accepted Answer

Developer Console's Logs panel with the log level set to FINEST for the Apex Code category and the user filter applied.. Granular trace flags scoped to one user, combined with the Developer Console's log inspection and execution timeline, expose CPU time, cumulative resource usage, and individual SOQL statements at the FINEST level. This isolates the expensive code path while avoiding org-wide verbose logging, which would degrade performance and consume log storage.

Answer

Event Monitoring's ApexExecution event type queried through the EventLogFile object to obtain per-transaction CPU metrics.

Answer

Apex Replay Debugger launched against a production org with the Apex Interactive Debugger enabled for all users.

Answer

Setup Audit Trail filtered by the affected user to review the sequence of Apex executions and their CPU consumption.

Question 7

A developer is preparing to deploy a new Lightning Web Component (LWC) that includes an Apex controller. The deployment will be done using a change set. The developer needs to ensure that the Apex controller's test class meets all requirements for production deployment. Which two actions should the developer take? (Choose two.)

Accepted Answer

Ensure the test class covers at least 75% of the Apex controller's code.. To deploy an Apex controller to production, the test class must provide at least 75% coverage of the controller's code and include assertions that validate the controller's behavior. These two actions ensure that the code is adequately tested and meets Salesforce's deployment requirements. Other considerations like avoiding SeeAllData and efficient execution are good practices but not mandatory for this scenario.

Answer

Annotate the test class with @isTest and make it private.

Answer

Ensure the test class runs in under 10 minutes to avoid deployment timeouts.

Answer

Use @isTest(SeeAllData=true) to access real data and improve coverage.

Question 8

A developer is preparing to deploy a new Apex class and a Lightning web component to production. The deployment fails with the error: 'You can't change the API version of an installed package component.' The developer's package is not managed, but the org has a managed package installed that includes a class with the same name. Which action should the developer take to resolve the deployment error?

Accepted Answer

Rename the Apex class to avoid a naming collision with the managed package component.. The error occurs because the deployment attempts to modify a component that belongs to an installed managed package. Renaming the Apex class avoids the collision and allows the deployment to proceed. Managed package components are immutable, so the developer must choose a different name for the new class.

Answer

Change the API version of the new Apex class to match the managed package's API version.

Answer

Uninstall the managed package, deploy the new class, then reinstall the package.

Answer

Add the new class to a new managed package and deploy that package instead.

Question 9

A developer is deploying metadata to a production org using the Salesforce CLI. The deployment must create a custom object, deploy its fields, and then run Apex tests, but the developer wants each component type validated in a specific order and wants a pre-deployment destructive change to remove an obsolete field. Which capability directly supports this need?

Accepted Answer

A destructiveChanges.xml file paired with the main manifest, passed through the sf project deploy start command.. Removing an obsolete field while deploying new components is a destructive change, which the Metadata API handles through a dedicated destructiveChanges.xml manifest submitted together with the constructive manifest. The CLI exposes this through sf project deploy start, and the platform then processes creations, updates, and deletions internally while running the requested Apex tests.

Answer

A post-deployment script defined in the sfdx-project.json configuration that issues a deleteMetadata call.

Answer

A .forceignore file in the project root that excludes the obsolete field from the deployment.

Answer

A package.xml manifest that lists the components in the desired deployment sequence.

Question 10

A developer is preparing to deploy a new Apex class and a Lightning web component from a sandbox to production using a change set. The developer wants to ensure the deployment succeeds and that the new functionality works as expected after deployment. (Choose two.)

Accepted Answer

Run all local Apex tests in the sandbox and confirm that code coverage for the new Apex class meets the 75% requirement. Before deploying, running local Apex tests confirms that the new class meets the 75% coverage requirement and that existing tests still pass. The change set must then include the Apex class, its test class, and the Lightning web component bundle so that production validation can run the tests and the component is available. Together these steps ensure the deployment succeeds and the functionality is present after deployment.

Answer

Set the deployment test level to RunLocalTests in the change set deployment options to run all tests in the production org

Answer

Deploy the change set without running tests, then run the new Apex class's tests manually in production to verify coverage

Answer

Use the Force.com Migration Tool to retrieve the metadata from the sandbox and deploy it to production instead of using a change set

Question 11

A developer is building a Lightning Web Component that needs to communicate with a parent Aura component. The LWC is nested inside the Aura component. The developer wants to send data from the LWC to the Aura component. Which two methods can be used to achieve this? (Choose two.)

Accepted Answer

Dispatch a standard DOM CustomEvent from the LWC that the Aura component listens for using an event handler in its markup.. The two correct methods are dispatching a standard DOM CustomEvent that the Aura component can listen for, and using Lightning Message Service to publish and subscribe to messages. Both are supported patterns for communication from LWC to Aura. The other options either describe the reverse direction (Aura to LWC) or attempt to access internal state, which is not allowed.

Answer

Use the Aura component's controller to call a method on the LWC using the LWC's public API.

Answer

Access the Aura component's attributes directly from the LWC using this.template.host or similar DOM traversal.

Answer

Call a public method on the Aura component using the Aura component's aura:method from the LWC.

Question 12

A developer is investigating why an Apex test method intermittently fails in a continuous integration pipeline but passes locally. The test asserts on records created by a Queueable job that chains another Queueable. Which TWO practices should the developer apply to make the test deterministic? (Choose two.)

Accepted Answer

Ensure the test creates its own data with @TestSetup or within the method, then use Test.stopTest before asserting on the chained job's results.. Deterministic coverage of a Queueable chain requires forcing the asynchronous work to complete inside the test transaction and removing dependence on ambient org data. The Test.startTest and Test.stopTest boundary executes queued jobs synchronously so assertions run after the chain finishes, while self-contained data creation keeps results stable across orgs and pipeline runs.

Answer

Increase the Apex test timeout by adding @isTest(seeAllData=true) to the test class so the asynchronous job has time to finish.

Answer

Use Test.getEventBus and Test.enqueueJob to control scheduling of the queued jobs within the test.

Answer

Call Test.isRunningTest inside the Queueable to skip the chained second job during tests.

Question 13

A developer is using the Apex Replay Debugger in VS Code to debug a complex issue. The developer has captured a debug log from a production org and wants to replay it locally. Which statement accurately describes a limitation or requirement of the Apex Replay Debugger?

Accepted Answer

The debug log must be generated with the 'Apex Code' debug level set to at least FINE to capture variable assignments and checkpoints.. The Apex Replay Debugger relies on debug logs that contain variable assignments and checkpoint information. This is captured when the Apex Code debug level is set to FINE or higher. Other debug levels, such as Apex Profiling, are not required. The debugger works offline, so user permissions and live data access are irrelevant.

Answer

The debug log must be generated with the 'Apex Code' debug level set to at least FINE and include the 'Apex Profiling' level for checkpoints.

Answer

The debug log must be from a user with the 'View All Data' permission to access all records involved.

Answer

The debug log must be generated with the Apex Code debug level set to FINEST to capture all variable assignments.

Question 14

A developer is building a Lightning Web Component that displays a list of contacts for a given account. The component uses the getRecord wire adapter to retrieve the account's contacts. The developer wants to ensure the component updates automatically when the contact records change on the server. Which two actions should the developer take? (Choose two.)

Accepted Answer

Use the refreshApex function to refresh the wired data after performing an update to the contact records.. To ensure the component updates when contact records change, the developer should use refreshApex to manually refresh the wired data after updates, and notifyRecordUpdateAvailable to inform the Lightning Data Service of record changes. These two functions work together to invalidate caches and trigger re-fetching, keeping the UI in sync with server-side changes.

Answer

Use the getRelatedListRecords wire adapter to fetch the contacts and rely on its built-in refresh capabilities.

Answer

Use the getRecord wire adapter with the appropriate fields and ensure the component is within a record page context.

Answer

Subscribe to the lightning:empApi channel to receive notifications when contact records change.

Question 15

A developer is building a Lightning Web Component that must display a custom UI in a Visualforce page using Lightning Out. The component uses the lightning/navigation module to navigate to a record page. When the component is rendered in the Visualforce page, the navigation fails. What is the most likely cause?

Accepted Answer

The navigation service requires the Lightning Experience container, which is not present in a standalone Visualforce page.. The lightning/navigation service is designed to work within the Lightning Experience container. When a Lightning Web Component is used in a Visualforce page via Lightning Out, it runs outside that container, so navigation calls fail. The correct solution is to ensure the component runs in a supported context or use an alternative navigation method.

Answer

The component must use the NavigationMixin from lightning/navigation instead of the navigation module.

Answer

The Visualforce page must include the lightningOut.js script and define a Lightning Out app.

Answer

The lightning/navigation module is not supported in Lightning Out.

Question 16

A developer is creating a Lightning Web Component that renders a list of contacts fetched imperatively with getRecord or a wire adapter. Each row has a button that opens a custom modal defined in the same component. The developer wants the modal markup to exist in the DOM only while it is open, and wants to avoid a full page navigation. Which approach best satisfies these requirements?

Accepted Answer

Use if:true on a template element wrapping the modal markup and toggle a boolean property when the button is clicked.. Conditional rendering with the if:true directive adds or removes the wrapped markup from the DOM based on a tracked boolean, which satisfies both the visibility requirement and the no-navigation requirement. Hiding with CSS, using unsupported base components, or navigating away all fail one of the stated goals.

Answer

Apply the slds-hide CSS class to the modal container and toggle the class when the button is clicked.

Answer

Navigate to a separate Lightning page using NavigationMixin and pass the record id in the state.

Answer

Use the lightning-modal-base component and set its open attribute to false initially.

Question 17

A developer is building a Lightning Web Component hosted inside a Visualforce page via lightning:container. The component needs to invoke an Apex method that returns sensitive data. The developer wants the call to run in the user's context and respect Apex sharing rules, without exposing the method to unauthenticated callers. Which approach should be used?

Accepted Answer

Annotate the Apex method with @AuraEnabled and call it from the component with an imperative import, relying on the user's session for authentication.. Invoking an @AuraEnabled Apex method imperatively from a Lightning Web Component uses the current user's authenticated session, so authentication is inherent and Apex sharing rules apply. Cacheable wiring is meant for read-only, cache-tolerant data, while REST resources and global classes do not provide the same straightforward, secure invocation path for this scenario.

Answer

Mark the Apex class as global and call the method directly from JavaScript using the class name.

Answer

Annotate the Apex method with @AuraEnabled(cacheable=true) and call it from the LWC using a wired property.

Answer

Expose the Apex method through a @RestResource and call it with fetch from the component.

Question 18

A developer is creating a Lightning Web Component that must render a list of contacts and allow inline editing of the phone field. The component should use base Lightning components for the form and handle the save operation with Apex. Which TWO approaches are valid for ensuring the component updates the UI after a successful save? (Choose two.)

Accepted Answer

Call the updateRecord function from lightning/uiRecordApi and rely on the wire adapter to automatically refresh.. To update the UI after a successful save, developers can use refreshApex on a getRecord wire adapter after an Apex DML operation, or use updateRecord from lightning/uiRecordApi, which automatically updates the wire cache. Directly mutating wire data or manually reassigning client-side arrays does not properly refresh the data and can cause inconsistencies. These two approaches are the supported patterns for keeping the UI in sync with server-side changes.

Answer

Reassign the component's contact list property with a new array constructed from the old data plus the updated phone value.

Answer

Directly mutate the array returned by the wire adapter and reassign it to a tracked property.

Answer

Use the refreshApex function on a wired Apex method that returns the contacts, after the save Apex method completes.

Question 19

A developer is building a Lightning Web Component that must call an Apex method imperatively and handle errors gracefully. The component needs to show a toast when the call fails and must also pass parameters to the Apex method. Which TWO practices are correct for this scenario? (Choose two.)

Accepted Answer

Pass parameters to the Apex method by supplying an object as the argument to the imported function, with keys matching the Apex method's parameter names.. Imperative Apex calls are made by importing the method from @salesforce/apex and invoking it with a single object of parameters. Error handling is done with try/catch, and toasts are shown in the catch block. The cacheable annotation is not required for imperative calls and does not auto-display errors. Wire is a different model and does not fit the imperative requirement.

Answer

Import the Apex method from lightning/apex and invoke it with the parameters as separate positional arguments.

Answer

Decorate the Apex method with @AuraEnabled(cacheable=true) so that errors surface automatically as toasts.

Answer

Use the @wire decorator with the Apex method and read the error property to display toasts, since wire automatically retries failed calls.

Question 20

A developer is building a Lightning Web Component that must call an Apex method that performs a callout. The component is placed on a Lightning record page, and the Apex method is annotated with @AuraEnabled(cacheable=true). Users report that the callout never executes and an error is thrown. What is the most likely cause and the correct fix?

Accepted Answer

The callout is blocked because @AuraEnabled(cacheable=true) methods cannot perform callouts; remove cacheable=true or move the callout to a method without caching.. Apex methods annotated with @AuraEnabled(cacheable=true) run in a read-only context that prohibits callouts and DML. When such a method attempts a callout, Salesforce throws an error before the callout is made. The correct resolution is to remove cacheable=true or to move the callout into a separate non-cacheable method that the component invokes directly, allowing the callout to proceed while keeping any cacheable read logic separate.

Answer

The callout is blocked by the component's Lightning locker service; disable locker service for the component in Setup.

Answer

The error occurs because the Apex method must be annotated with @AuraEnabled(cacheable=true) to allow callouts; add the annotation.

Answer

The callout fails because Lightning Web Components cannot call Apex methods that perform callouts; use a Visualforce remoting call instead.