>HTTP 400 level errors on their own do not indicate a problem. ...on the back-end, but they can help find issues with the front-end. For example: I have an end

>HTTP 400 level errors on their own do not indicate a problem. ...on the back-end, but they can help find issues with the front-end. For example: I have an endpoint my front-end calls in the background to update a preview for the user, I found out that some changes in the front-end made all calls invalid (but only in production), monitoring 400 errors helped me figure out the issue very quickly before a customer even complained about it. Sometimes, "the client screwed up" because of you, if you have 90% of your clients messing up in the exact same way it may actually be your fault.