1. A computer-implemented method, comprising: receiving, at a source code management (SCM) repository maintained by a node executing on a computing device, updated application code of an application executed on the node, wherein the node is provided by a multi-tenant Platform-as-a-Service (PaaS) system; providing, by the node, the updated application code to one or more cartridge instances that implement framework of the application; determining, by each of the one or more cartridge instances, that a marker file is present in the updated application code, the marker file indicating that hot deployment functionality is to be implemented for the application; and implementing, by each of the one or more cartridge instances using hot deployment functionality that is specific to the cartridge instance, code changes in the updated application code without a restart of the application.