Rate limiting is used to control amount of traffic sent or received by a network. For example, if you are using a certain API which is configured to allow 1000 requests per minute, your call will fail after hitting the limit, typically resulting 429 return code. This is a commonly used practice for a better flow of data and to increase security by mitigating attacks such as DoS.
Forge has rate limiting as well. When you are writing a code for scalable solution, you will need to take it into consideration; i.e., When you hit a limit, you will need to wait till given period has lapsed and retry. 429 response will contain “Retry-After” http header, which indicates the number of seconds after which the client can call again. Below is an example of response when hitting a limit: