LWC with Apex: Best Practices for Scalable Salesforce Development
Lightning Web Components (LWC) empower developers to build fast, modern, and reusable UI in Salesforce. But the real power of LWC comes when it works hand-in-hand with Apex to fetch, manipulate, and persist Salesforce data.
In this blog, we’ll walk through the best practices for integrating LWC with Apex — covering performance, reusability, and scalability.
🔹 1. Choose the Right Approach: @wire vs Imperative Apex Calls
There are two main ways to invoke Apex from LWC:
✅ @wire (Reactive & Cache-Friendly)
- Best for read-only or frequently accessed data.
- Supports automatic refresh and Lightning Data Service caching.
import { LightningElement, wire } from ‘lwc’;
import getAccounts from ‘@salesforce/apex/AccountController.getAccounts’;
export default class AccountList extends LightningElement {
@wire(getAccounts) accounts;
}
✅ Imperative Apex Call (On-Demand)
- Best for button clicks, form submissions, or conditional logic.
- More control over execution and error handling.
import { LightningElement, track } from ‘lwc’;
import getAccounts from ‘@salesforce/apex/AccountController.getAccounts’;
export default class AccountList extends LightningElement {
@track accounts;
handleClick() {
getAccounts()
.then(result => {
this.accounts = result;
})
.catch(error => {
console.error(error);
});
}
}
👉 Best Practice: Use @wire for reactive reads and imperative for user-triggered actions.
🔹 2. Keep Apex Methods Bulkified and Reusable
Apex is running server-side, so always design methods to:
- Handle multiple records at once (List<Id> instead of single Id).
- Avoid SOQL/DML inside loops.
- Keep logic reusable for multiple LWCs.
public with sharing class AccountController {
@AuraEnabled(cacheable=true)
public static List<Account> getAccounts(Set<Id> accountIds) {
return [SELECT Id, Name, Industry FROM Account WHERE Id IN :accountIds];
}
}
👉 Best Practice: Even if LWC calls with a single Id, write Apex to accept collections.
🔹 3. Leverage @AuraEnabled(cacheable=true) for Performance
- Mark read-only methods with cacheable=true.
- Improves performance by using Lightning Data Service (LDS) cache.
- Reduces server round-trips.
@AuraEnabled(cacheable=true)
public static List<Contact> getContactsByAccount(Id accountId) {
return [SELECT Id, Name, Email FROM Contact WHERE AccountId = :accountId];
}
👉 Best Practice: Use only on queries (no DML).
🔹 4. Handle Errors Gracefully
Always catch and surface errors in LWC.
getAccounts()
.then(result => {
this.accounts = result;
})
.catch(error => {
this.errorMessage = error.body ? error.body.message : error.message;
});
👉 Best Practice: Provide meaningful messages for users (e.g., “No records found” instead of raw Apex exception).
🔹 5. Optimize Data Usage
- Query only the fields you need.
- Use SOQL selective filters (avoid SELECT *).
- Paginate or lazy-load data for lists.
Example of paginated Apex:
@AuraEnabled(cacheable=true)
public static List<Account> getAccounts(Integer offsetSize, Integer limitSize) {
return [SELECT Id, Name FROM Account ORDER BY CreatedDate DESC LIMIT :limitSize OFFSET :offsetSize];
}
🔹 6. Secure Your Apex Code
- Always use with sharing unless there’s a strong reason otherwise.
- Enforce CRUD/FLS in Apex using Schema.sObjectType.
- Validate user input (especially in search filters).
if (!Schema.sObjectType.Account.fields.Industry.isAccessible()) {
throw new AuraHandledException(‘Insufficient permissions to view Industry field’);
}
👉 Best Practice: Don’t rely only on profile/permission set — validate in Apex.
🔹 7. Minimize Network Calls
- Batch related queries in one Apex call.
- Avoid chaining multiple server trips when data can be retrieved at once.
- Use Composite API (for external integration) if you need multiple objects at once.
🔹 8. Testing & Mocking Apex in LWC
- Write Apex tests with test data (no seeAllData=true).
- For LWC Jest tests, mock Apex calls using @salesforce/apex/… import stubs.
✨ Final Thoughts
Integrating LWC with Apex is where Salesforce front-end meets back-end power. By following these best practices:
- Use @wire for reactive reads and imperative calls for user actions.
- Bulkify and secure Apex.
- Use caching for performance.
- Handle errors gracefully and query only what you need.