Yeah, I hate APIs that return 200 with a JSON (or XML) body that says the response was anything but OK.<p>Another bugbear is a server suddenly switching content types for errors. If you&#x27;re on IIS, make sure you&#x27;re handling your own damn error pages so I don&#x27;t suddenly have to account for an HTML 500 error page in my javascript code. Cisco&#x27;s AXL API was a terrible offender for this one.