Use Chrome developer tools.

With the Chrome developer tools you can inspect which requests BOA is sending to your API. This way you can analyse the speed of your endpoints.

For all the information about this, you can look here.

Checking the content of the requests that are send to your iAPI will give you a lot of info in case of problems. You will see the command that is used: Get, Post, Put, Delete and you will see the paramaters that were send. In case of a PUT or POST you can also analyse the JSON data that is send. It will make your life easier.