An API isn’t stronger than its weakest link and what’s often ignored in the ongoing maintenance and development of an API is the constant effort required to provide great self-servicable error messages. What this means is that without great, user-friendly error messages, your API is not going to be great.
Just think about your first interaction with an API. How many failing requests have you sent before you have dug yourself through swathes of error messages and documentation to get to that one penultimate successful request making your heart sing and fists shaking in the air?

Great error messages make them not feel like errors, but like friendly guidance towards a working request. They should be detailed enough to let the developer fix whatever problem there is themselves, like a dialogue between a customer and a support technician.

This talk will give you ideas of how to handle errors and exceptions that occur in your application, be it with the incoming request, database failures or errors received from a 3rd party and how to serialize them into user friendly and actionable problem messages.