Zuul provides a range of different types of filters that allows us to quickly and nimbly apply functionality to our edge service. The filters perform the following functions:

Authentication and Security: It provides authentication requirements for each resource.

Insights and Monitoring: It tracks meaningful data and statistics that give us an accurate view of production.

Dynamic Routing: It dynamically routes the requests to different backed clusters as needed.

Stress Testing: It increases the traffic to a cluster in order to test performance.

Load Shedding: It allocates capacity for each type of request and drops a request that goes over the limit.

Static Response Handling: It builds some responses directly at the edge instead of forwarding them to an internal cluster.

Multi-region Resiliency: It routes requests across AWS regions in order to diversify our ELB usage.

https://www.javatpoint.com/zuul-api-gateway