Systems and methods are described for implementing a distributed unit in a radio access network that executes code on behalf of mobile devices. A distributed unit may be implemented on an edge server that is in close physical proximity to a radio unit, with few or no intervening devices. The edge server may thus provide services to mobile devices, such as executing code on behalf of a mobile device in an execution environment on the edge server, at significantly lower latency than more distant cloud-based servers. The edge server may preload computing environments with code for which a mobile device is likely to request execution (e.g., because a particular application is executing on the mobile device), and may determine whether to execute code on the edge server or on a cloud provider network.