REI Systems – Salesforce Developer Interview Questions
What's Covered
Topics covered in this interview.
01Lightning Web Components7
02Salesforce Core Concepts1
03General & Experience8
All Interview Questions
Every question asked in this interview, listed one by one.
1Can one use LWC in lightning app builder?
2What are advantages of LW over Aura?
3When we have to with Aura Components over LWC.
4Write Syntax for calling Apex from LWC.
5Are quick actions supported for LWC?
6When we create new component why does it say export default ComponentName?
7Can we access one lightning component inside another lightning component in salesforce?
8What is integration?
9Code: Given an array find most frequent number and its frequency.
10What is Lighting app Builder?
11When to use force:recordData and when not to?
12Write Syntax for child to parent communications.
13How to avoid hard coding while using static resources?
14What is meaning of Call In and Call Out?
15What are remote site settings?
16How to read root elements in XML DOM?
More Salesforce Interview Questions to Practice
The extra questions below are not from this interview. They cover the same topics and are commonly asked in Salesforce developer interviews, so they make good practice before your own round.
Lightning Web Components questions
- What is shadow DOM, and what is synthetic shadow in LWC?
- How do you write Jest tests for a Lightning web component?
- How can a parent component call a public method of a child component?
- What are the main differences between Aura components and LWC?
- What are the lifecycle hooks of a Lightning web component, and in what order do they run?
Apex questions
- What is the difference between Database.insert and the insert DML statement?
- What is the difference between Batch Apex, Queueable Apex, Future methods and Schedulable Apex?
- When would you use a List, a Set and a Map?
- What is the order of execution when a record is saved?
Triggers questions
- How do you test a trigger with 200 records?
- What is the difference between addError on a record and addError on a field?
- What happens when a trigger and a record-triggered Flow run on the same object?
- What are the trigger context variables?
Integration questions
- What is the difference between the REST API and the SOAP API in Salesforce?
- What are Named Credentials, and why should you use them?
- How do you make an HTTP callout from Apex, and how do you test it with HttpCalloutMock?
General and experience questions
- How do you approach debugging a production issue?
- How do you decide between a declarative and a programmatic solution?
- Which best practices do you follow in Apex and LWC?
Concepts to Revise
Based on the questions on this page, these are the areas most worth revising.
Lightning Web Components
- Lifecycle hooks: constructor, connectedCallback, renderedCallback, disconnectedCallback
- Decorators: @api, @track, @wire and when each is needed
- Parent to child and child to parent communication using properties and custom events
- Lightning Data Service and the uiRecordApi functions
- Calling Apex: wire versus imperative, and cacheable methods
- Template directives: if:true, for:each, key and lwc:if
Apex
- Governor limits for SOQL, DML, CPU time and heap size
- Bulkification: no SOQL or DML inside loops
- Sharing keywords and how they affect record access
- Asynchronous Apex: future, queueable, batch and schedulable
- Test classes: test data, System.assert, Test.startTest and Test.stopTest
- Collections and wrapper classes
Triggers
- Context variables: isBefore, isAfter, isInsert, isUpdate, isDelete, isUndelete
- Trigger.new, Trigger.old, Trigger.newMap and Trigger.oldMap, and in which events each exists
- One trigger per object with a handler class
- Preventing recursion with static variables
- addError to block a save with a message
- Testing triggers with single and bulk records
How to Prepare
The questions on this page lean towards Lightning Web Components, Apex and Triggers. Spend most of your revision time there, then cover the remaining topics lightly.
- Build one small component that uses @wire, an imperative Apex call and a custom event, and be ready to explain each part.
- Practise explaining governor limits and bulkification with a real example from your own project.
- Write a trigger with a handler class from memory, then test it with 200 records to prove it is bulk safe.
- Say your answers out loud. Interviewers listen for clear, structured explanations, not memorised definitions.
- Prepare one or two real examples from your own projects for the general questions.
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