1. A method, comprising: receiving, by a processing device executing a virtual machine (VM) of a multi-tenant Platform-as-a-Service (PaaS) system, updated application code of an application executed on the VM, the updated application code sent to a source code management (SCM) repository maintained at the VM, wherein the VM hosts multiple applications that are each owned by different owners; providing, by the processing device, the updated application code to a cartridge instance that implements framework of the application on the VM, wherein the cartridge instance provides at least one of configuration templates, configuration scripts, or dependencies to execute source code of the application on the VM and wherein the cartridge instance is deployed on the VM from a master cartridge maintained by the multi-tenant PaaS; determining, by the processing device via the cartridge instance, 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 the processing device using the hot deployment functionality that is specific to the cartridge instance, code changes in the updated application code without a restart of the application.