in ur youtube video user request comes to a service and responce is sent using another service to user... how does another service knows the user IP

[sarathAvantari]

in this example which u have said.. user makes request through api gateway and after Executing all of the events he wil get the response , that means requeset originated from api gateway it know the user addres to send responce, but another service is sending responce , how another service know the user address.. NOTE: are u storing requeest IP any where so send responce to user..

[javatarz]

API gateways generally act as "transparent proxies" meaning they forward the request. As part of the request being forwarded, certain headers are added. The downstream service knows how to interpret these headers and return the result to the correct sender because this is a standard protocol. You can look up transparent proxies to understand how this works.