10 Essential Ruby on Rails Best Practices for Building Scalable Web Applications

‍

Building scalable web applications is critical for any Ruby on Rails project. Scalability ensures our application can handle increasing loads and continue to perform well as your user base grows. Here are ten essential best practices to help you build scalable Ruby on Rails applications.

1. Use the Right Gems

Choosing the right gems can significantly impact your application's performance and scalability. Avoid using too many gems, as they can bloat your application and increase load times. Stick to well-maintained, popular gems that are optimized for performance. Some recommended gems for scalability include:

- Puma: A fast, multi-threaded web server for Ruby/Rack applications.

- Sidekiq: Efficient background job processing for handling asynchronous tasks.

- Active Model Serializers: Optimizes JSON serialization, which is crucial for API performance.

We use these Puma gem in our applications that help us handle a large user base.

Sidekiq gem is used to run background jobs where we process thousands of user data without interrupting the usual user activities. This is supported along with redis.

Our experience: processing a large user data

We had a task in hand for a fantasy gaming project, which required us to calculate scores of thousands of users on their multiple line ups for a fantasy gaming platform. We were able to achieve this by using Sidekiq gem by batching the score calculation jobs in redis and processing them in sidekiq which runs the processes in multiple threads to calculate the score and to provide uninterrupted service to current user activities on the server.

2. Optimize Database Queries

Efficient database queries are vital for maintaining performance as your application scales. Follow these tips to optimize your queries:

- Use Indexes: Index frequently queried columns to speed up search operations.

- Eager Load Associations: Use `includes` to load associated records in a single query, reducing N+1 query problems.

- Avoid SELECT * Queries: Specify only the fields you need to reduce data transfer and memory usage.

Some of the best optimization practices we follow in our projects are to check for any query that might be delaying an API response and try to address it as quickly as possible. Most of the time this could  be a query running inside a loop.

This can be easily eliminated by using a variable to save an indexed object of a desired key using a single query outside the loop and simply referencing the index from the variable wherever necessary.

Our experience: Exponential improvement in response and processing times

In one of our applications with a large user base, there was very slow response time. We identified the issue on less optimum queries and querying techniques.
We were able to reduce the response time up to 60% by using optimized queries and indexing the database columns when and where they were frequently used to filter data.

Adding to this we used batching of processes to make our processing more efficient and resilient. Which resulted in a reliable application to handle large volumes of data and user requests. 

3. Implement Caching

Caching can drastically reduce load times and server load. Ruby on Rails offers several caching mechanisms:

- Fragment Caching: Cache parts of your views to avoid rendering them repeatedly.

- Page Caching: Cache entire pages for static content.

- Action Caching: Cache the output of entire controller actions.

Leverage caching to store frequently accessed data and reduce the load on your database and server.

4. Background Jobs and Asynchronous Processing

Background jobs allow you to offload time-consuming tasks to be processed asynchronously. This improves user experience and application performance. Use background job frameworks like Sidekiq or Resque to handle tasks such as:

- Sending emails

- Processing file uploads

- Data processing

Ensure that your background jobs are idempotent and can handle failures gracefully.

To ensure our background jobs are reliable and resilient we practice batch processing.

Processing data in batches enables us  to recover and retry the batches in case of failure instead of retrying the whole process. 

This also helps us to reduce the load on servers as the data is processed in batch to reduce the chance of failures.

Our experience: Making background jobs more resilient 

In one of our applications which processes large chunks of data, we found some of the data to have not been processed. This was not a logical issue in code as there was other correct information coming from the code. 

Upon investigation we found the issue was with the background processor not able to handle the large data set which was given to it. We handled it effectively with batching the process to lower the load on the server and since the batch we have had very reliable operations of our application.

5. API Rate Limiting and Throttling

Rate limiting protects your application from abuse and ensures fair usage of resources. Implement rate limiting to control the number of requests a user can make within a given time frame. You can use gems like **Rack::Attack** to set up rate limiting and throttling rules for your APIs.

We can set a number for requests that can be made from a single IP address per minute and this prevents any single user or potentially bots from overwhelming our systems.

Our experience: Securing from DDoS attacks

In one of our recent projects, we audited and found the vulnerability of a DDoS attack, which could overwhelm our Ruby on Rails application with excessive requests. To mitigate this, we implemented rate limiting using the **Rack::Attack** gem. We configured Rack::Attack to limit the number of requests from a single IP address per minute, effectively preventing any single user or bot from overloading our system. This approach successfully protected our application from abuse, ensuring fair resource usage and maintaining system stability.

6. Use Content Delivery Networks (CDNs)

CDNs improve the delivery speed of your assets by distributing them across multiple servers worldwide. Using a CDN reduces the load on your server and decreases latency for users. Configure your Rails application to serve static assets (images, CSS, JavaScript) via a CDN for better performance.

7. Security Best Practices

Security is paramount in any scalable application. Follow these best practices to secure your Rails application:

- Use Strong Parameters: Protect against mass assignment vulnerabilities.

- Sanitize Inputs: Prevent SQL injection and cross-site scripting (XSS) attacks.

- Encrypt Sensitive Data: Use Rails' built-in encryption to protect sensitive information.

Regularly update your gems and Rails version to benefit from security patches and improvements.

Our experience: Securing the application

In a recent project for an entertainment business company, we enhanced our Ruby on Rails application's security by implementing several best practices. We used Strong Parameters to prevent mass assignment vulnerabilities and sanitized all user inputs to guard against SQL injection and XSS attacks. Additionally, we encrypted sensitive data using Rails' built-in encryption methods. Regularly updating our gems and Rails version ensured we benefited from the latest security patches and improvements. This comprehensive approach significantly strengthened our application's security, protecting it from various threats and ensuring the safety of user data.

8. Effective Testing Strategies

Automated testing ensures your application remains stable and scalable as you add new features. Use testing frameworks like RSpec or Minitest to write comprehensive tests:

- Unit Tests: Test individual models and methods.

- Integration Tests: Test interactions between different parts of your application.

- Performance Tests: Identify and address performance bottlenecks.

Ensure you have a robust CI/CD pipeline to run tests automatically.

It is a good practice for Ruby on Rails companies to create spec files alongside development changes to run tests during deployment, ensuring the code functions as expected.

Our experience: Integrated testing strategies

In one of our projects, we incorporated these tests into a robust CI/CD pipeline, which ran tests automatically during deployment. This practice ensured our code worked as expected and maintained application integrity with every change. By creating spec files alongside development changes, we continuously validated our application's functionality and performance.

9. Monitoring and Performance Tuning

Monitoring helps you identify and address performance issues before they affect your users. Use monitoring tools like **New Relic** or **Scout** to track key performance metrics:

- Response times

- Database query performance

- Error rates

In all our projects we regularly review and optimize your application based on monitoring data.

We always make it a habit to check the response time of each and every end point while developing in order to fill the gaps of optimization as and where required.

This also helps us to produce highly scalable applications which can cater to the users without any compromise in the performance.

10. Deploying and Scaling with Cloud Providers

Deploying your Rails application on cloud platforms like AWS or Heroku provides scalability and reliability. Follow these best practices for cloud deployment:

- Use Auto-Scaling: Automatically adjust server capacity based on traffic.

- Implement Load Balancing: Distribute incoming traffic across multiple servers.

- Use Managed Databases: Leverage managed database services for automated backups, scaling, and maintenance.

Configure your infrastructure as code (IaC) using tools like Terraform or CloudFormation for reproducibility and scalability.

Our experience: Auto scaling applications

All our production applications are designed to scale up and scale down depending on the resource utilization. We set rules set in cloud services which monitor the resources and when the resources reach a certain threshold the services will scale up to provide uninterrupted experience to the end users regardless of the traffic.

This has been reliable in having uninterrupted service and also cost effective when we scale down during low traffic hours.
‍

Conclusion

Building scalable Ruby on Rails applications requires a combination of best practices, efficient tools, and careful planning. By implementing these ten best practices, you can ensure your application is prepared to handle growth and deliver a seamless experience to your users. Stay updated with the latest Rails features and continuously optimize your application to maintain scalability.

With Techjays, you can build your web applications in just a few clicks. Get in touch with us today.