Rate limiting is a common technique used to improve the security and durability of a web application.
For example, a simple script can make thousands of web requests per second. Whether malicious, apathetic, or just a bug, your application and infrastructure may not be able to cope with the load. For more details, see Denial-of-service attack. Most cases can be mitigated by limiting the rate of requests from a single IP address.
Most brute-force attacks are similarly mitigated by a rate limit.
This method of rate limiting is cumbersome, but has some advantages. It allows throttling of specific paths, and is also integrated into Git and container registry requests. See Rack Attack initializer.