This article was adapted from a Google Tech on the Toilet (TotT) episode. You can download a printer-friendly version of this TotT episode and post it in your office.
By Arham Jain
 

Is your code a tangled mess of business logic and side effects? Mixing database calls, network requests, and other external interactions directly with your core logic can lead to code that’s difficult to test, reuse, and understand. Instead, consider writing a functional core that’s called from an imperativ​​e shell.