As was said before, error handling is extremely important. It is important to gracefully inform the user about failures if they happen and, even more important, to not leave any loose exceptions so that they don't kill Android applications, completely ruining the user experience.
There are multiple ways of implementing exception handling in RxJava. We will learn how to use methods such as doOnError() or onExceptionResumeNext() to gracefully adjust the flow when an error occurs.