Over the last several years, processing power in mobile devices has increased considerably. Users are demanding richer experiences and one method of achieving improved performance on modern mobile devices is via multithreading. Most mobile devices today are powered by multicore processors, and their operating systems now offer developers easy abstractions for executing code in the background, without interfering with the performance of the app's UI.
This recipe will cover both the use of iOS's Grand Central Dispatch (GCD) to execute asynchronous background processing on a new thread, and communicating back to the React Native layer when the processing is complete.