Why your Ruby on Rails application has high CPU usage?

Have you ever received an alert saying: CPU usage is above 90% Or maybe one of your production servers suddenly became slow, requests started timing out, and users began reporting performance issues. As Rails engineers, one of the most common production incidents we face is unexpectedly high CPU utilization. The tricky part? High CPU usage is rarely the actual problem. It's usually a symptom of something else happening inside your application, infrastructure, database, background jobs, or even your code architecture. I will explore the most common reasons behind high CPU consumption in Ruby on Rails applications. won't go too deep into each topic because every single one deserves.