Salesforce interview prep

Learn Apex. Then prove you can write it.

Lessons, interview questions and mind maps, plus a code editor that runs in your own Salesforce org. Connect a Developer Edition org to start.

19 short lessons
45 interview questions
Code runs in your org

Lists, Sets and Maps · Problem 3

Count records per Account

+200 points

public static Map<Id, Integer> countByAccount(List<Contact> contacts) {
  Map<Id, Integer> counts = new Map<Id, Integer>();
  for (Contact c : contacts) {
    Integer n = counts.get(c.AccountId);
    counts.put(c.AccountId, n == null ? 1 : n + 1);
  }
  return counts;
}

✓

Executed in your-org.my.salesforce.com

All assertions passed · +200 points

01 Practice

Write Apex in your org

Problems run against the org you connect. Passing one earns points.

Learn the idea first

Short chapters on the language, triggers, limits, async Apex, testing and security.

Answer the question

Multiple choice by topic, with an explanation after every answer.

See how it fits together

Visual maps for the Lightning design system, CSS and interfaces.

How it works

Learn it, test it, then write it.

01
Connect your dev org

Log in with Salesforce using a Developer Edition org. That org becomes the place where your code runs.
02
Learn it, then test it

Read a short lesson, answer the interview questions, and use a mind map when you want the whole picture.
03
Prove it in Apex

Write the code in the editor. It runs in your org, and a passing solution adds points to the leaderboard.

Practice tracks

Then practice the Apex you just learned.

Four coding tracks unlock as soon as your org is connected.

Logical problems

Operators, strings, switch, enums, exceptions, dates and records.

Beginner

Lists, Sets and Maps

Lists, sets and maps, including the case-insensitive key rules.

Beginner to intermediate

SOQL and SOSL

Query a sample data model in your org and match the expected result.

Intermediate

OOP and DSA

Classes, stacks, searching and sorting implemented in Apex.

Intermediate

Before you connect

What happens in your org.

Use a Developer Edition org that you're happy to practice in. Don't connect a production org.

Your code runs as anonymous Apex in the org you log in with.
The SOQL track asks you to install a small sample data model and create test records.
Your session lasts until you log out or close the browser tab.

Ready to write some Apex?

Connect your dev org and start the first track.