you should NEVER rely on ANY API Well that's a bit extreme, a better approach would be to acknowledge that your reliance on an external API is a risk that you'

you should NEVER rely on ANY API Well that's a bit extreme, a better approach would be to acknowledge that your reliance on an external API is a risk that you're taking in order to save the development costs of DIY. If it's critical to your system, you need to have as part of your risk management a plan B that you can either switch to, or develop in the background. But overall trading development time for some risk makes sense a lot of the time. Unless the API is something with no alternative, and not easy to replicate, then you have an issue.