Leaking is the wrong word. A leak implies that the memory was retained, RAM usage will go up forever and the process will eventually crash as a result. This is memory that sidekiq needs to do it&#x27;s job, allocating strings, hashes, arrays etc. that will all be cleaned up eventually. Larger, more complex objects take up more memory. I.e. strings take up less memory than a hash. What he has done is eliminate the need to allocate so many large objects. This means less GC is needed, and overall performance is increased.<p>See <a href="http:&#x2F;&#x2F;www.schneems.com&#x2F;2015&#x2F;05&#x2F;11&#x2F;how-ruby-uses-memory.html" rel="nofollow">http:&#x2F;&#x2F;www.schneems.com&#x2F;2015&#x2F;05&#x2F;11&#x2F;how-ruby-uses-memory.html</a> for more info.