Why background processing improves performance in Ruby on Rails - See It in Action

Why background processing improves performance

📖 Scenario: You are building a simple Rails app that sends welcome emails to new users. Sending emails can take time and slow down the app response.

🎯 Goal: Learn how to move email sending to a background job to keep the app fast and responsive.

📋 What You'll Learn

Create a User model with a name and email

Add a configuration variable to enable background jobs

Write a background job class to send welcome emails

Trigger the background job when a user is created

💡 Why This Matters

🌍 Real World

Many web apps send emails or process images after user actions. Doing this in the background avoids delays.

💼 Career

Understanding background jobs is essential for Rails developers to build scalable, user-friendly applications.

1

Create the User model

Create a Rails model called User with string attributes name and email.

Ruby on Rails

# Create User model with name and email
# Your code here

Need a hint?

Use rails generate model User name:string email:string and run migrations.

2

Add background job configuration

Add a configuration variable USE_BACKGROUND_JOBS set to true in an initializer file.

Ruby on Rails

class User < ApplicationRecord
  # Attributes: name:string, email:string
end

# Add USE_BACKGROUND_JOBS = true below
# Your code here

Need a hint?

Create a file in config/initializers or add at the bottom of application.rb.

3

Create a background job to send welcome emails

Create a background job class WelcomeEmailJob that has a perform(user_id) method to send a welcome email to the user with that ID.

Ruby on Rails

class User < ApplicationRecord
  # Attributes: name:string, email:string
end

USE_BACKGROUND_JOBS = true

# Create WelcomeEmailJob class with perform method
# Your code here

Need a hint?

Use rails generate job WelcomeEmail to create the job file.

4

Trigger the background job on user creation

In the User model, add an after_create callback that enqueues WelcomeEmailJob.perform_later(self.id) only if USE_BACKGROUND_JOBS is true.

Ruby on Rails

class User < ApplicationRecord
  # Attributes: name:string, email:string

  # Add after_create callback to enqueue WelcomeEmailJob if USE_BACKGROUND_JOBS is true
  # Your code here
end

USE_BACKGROUND_JOBS = true

class WelcomeEmailJob < ApplicationJob
  queue_as :default

  def perform(user_id)
    user = User.find(user_id)
    UserMailer.with(user: user).welcome_email.deliver_now
  end
end

Need a hint?

Use after_create callback and define a private method to enqueue the job.