A scalable recommendation engine includes stateless processors in communication with at least one memory server that stores contextual data. A router is configured to direct a recommendation request to a first stateless processor, which is configured to generate a recommendation using contextual data from the memory server. A controller monitors the available processing bandwidth of the stateless processors and deploys an additional stateless processor if the available processing bandwidth is less than a minimum available processing bandwidth threshold. The controller can remove from deployment a stateless processor if the available processing bandwidth is greater than a maximum pre-determined available processing bandwidth threshold.