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Optimization Tips for Ruby on Rails Applications

Ruby Performance Challenges

If you’re into web development, there’s a fair chance you’ve faced performance issues when working with Ruby on Rails. While Ruby offers many advantages, its performance can be challenging, particularly when the code complexity increases and leads to bottlenecks that don’t flag as bugs.

Performance isn’t the first quality that people think of when it comes to Ruby. Its benefits, while numerous, are oftentimes overshadowed by aspects such as high memory consumption and powerful meta-programming capabilities, which can lead to their own set of challenges.

Garbage Collection (GC) and Memory Management

In Ruby, garbage collection (GC) accounts for almost 80% of slowdowns and frequently takes more than 50% of your program’s execution time. It becomes more of an issue when you deal with data as objects, which require extra memory. Notably, prior Ruby versions (before 2.1), had an inefficient garbage collector that paused the application during its operation.

Reading Files

When reading files, it’s essential to keep in mind not to read the whole file at once as it can heavily burden your application’s performance. A single block of code that handles file reading, splitting lines, and other operations can take a significant toll on your application’s memory consumption.

Mutability and Memory Management

Ruby offers two versions of methods for dealing with object modifications – one version creates a new object while the other modifies the original object. By choosing to modify the original object, we can avoid the extra overhead of memory allocation. The same applies when dealing with arrays and hashes.

Coding Standards for Ruby Optimization Tips

A key principle to keep in mind to optimize your Ruby code is to avoid writing your code from scratch if a suitable gem for the task already exists. The Ruby on Rails framework abounds with libraries that make creating applications with Ruby a faster and more efficient process.

Database Utilization

Another crucial aspect is to allow the database to handle high request traffic by utilizing its features efficiently – a fact often overlooked by developers who use databases primarily as data storage tools. Proper usage of databases is a vital component of successful Ruby performance tuning.

Monitoring Tools

Application Performance Monitoring (APM) tools such as Raygun, can significantly enhance your coding productivity. They provide a steady eye on how your coding impacts performance and point out the parts in your Ruby code that are slow. Being aware of the responsible queries that slow down your pages is crucial.

Concatenating Strings & Memory Allocation

When it comes to concatenating strings, using the “<<” operator won’t create a new object in memory, hence you will avoid extra memory allocation. The commonly used way of concatenating strings with “+” creates new objects in memory and adds more pressure on GC.

Iterating In Ruby

Almost every Ruby developer uses the handy iterator methods provided by the language. However, keep in mind that these iterator methods can create temporary objects and exert pressure on the garbage collector. Opt for a while loop instead, and remove elements from the list as soon as they’re processed to optimize memory usage.

Going Beyond Ruby

Ruby is an impressive language, but it doesn’t mean you should write Ruby code all the time. C’s raw performance and advanced capabilities of databases can be beneficial for your code. Experience with other languages and tools can significantly contribute to improving Ruby’s performance. Just because you can do everything in Ruby doesn’t mean you should!

When to Use C

Like it’s rightly said, “When all you have is a hammer, everything looks like a nail”. While Ruby is a powerful tool, C’s raw performance can be much more effective in certain cases. Knowledge of where to leverage C’s potential over Ruby can make a huge difference in your application’s performance.

Getting More Out of Databases

Many developers frequently neglect the most advanced abilities of databases, using them only as glorified data storage tools. However, there’s so much more to databases that you can exploit to improve your application’s performance. Features like materialized views can significantly enhance the performance of your Ruby on Rails application.


In conclusion, while Ruby has some known issues, it can be optimized significantly by using the Ruby optimization tips provided above. By making use of performance monitoring tools, employing coding standards that prioritize memory management and effective utilization of databases, and understanding when to leverage the power of other languages such as C, you can significantly enhance the performance of your Ruby on Rails applications.

For more in-depth knowledge about deploying your Ruby on Rails applications, check the previous article here.

Stay tuned for our next article! 😉


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