Almost every modern web application somehow interacts with a backend - be it loading data, doing background sync, submitting a form, or publishing the metrics. Making API requests is not an easy task - we have to consider multiple outcomes and handle them properly. Otherwise, we might end up with confused users and decreased conversion. Although the stakes are high, it is still very likely to encounter an application designed with only a happy path scenario in mind. The question is - how can we improve it?