Disclosed are some implementations of systems, apparatus, methods and computer program products for implementing a scalable computing system. The scalable computing system includes an intermediate system that facilitates communications between a core server system and a third-party system. The core server system processes a client request for a third-party service in association with a web page having a corresponding web address. The intermediate system communicates with the core server system to obtain a session token, and transmits the session token and web address to the third-party system. The third-party system may then access the web page via the web address using the session token.