What is the optimal method for a Flex frontend to interact with a C# backend?

In what ways can a Flex frontend effectively connect with a C# backend, considering that the only available communication method is HTTP, without utilizing any custom sockets? My experience with SOAP has raised concerns about performance due to the significant overhead associated with XML, particularly since the current application demands high data processing. I am looking for a solution that offers a straightforward setup and seamless conversion processes. Is there a .NET equivalent of BlazeDS available?

you might want to see if using RESTful services could help! RESTful APIs using JSON instead of SOAP/XML have way less overhead, so they’re usually faster. not to mention it’s way easier to implement and debug imo