Hi, I have a general question to understand the performance impact if

Rahul,
The use case for using gateway nodes versus a rule event differs. The rule event should be used in the scenario that your process is waiting for a condition to evaluate to be true. An example could be to only activate quick tasks for a process when a Boolean status called active is set to true. From the documentation: You can use a Rule Event to monitor global constants and process variables. Each time a global constant or process variable is changed, the rule is reevaluated.

forum.appian.com/.../Rule_Event

The different gateways are to be used depending on how you need your flow to progress. More here:
forum.appian.com/.../Gateways

Thanks for the reply. But I am interested in get info about the backend functionality. If you provide some information about the same that will be great.

Just going by personal experience, if your use case works with a gateway, use that and not a rule. A rule event will be constantly monitored to see when it evaluates to true, whereas a gateway condition will only run once - when the gateway is encountered in the workflow. It seems pretty evident to me which one is more performant.

Thanks for the reply.