Implementations provide for a source to image framework for a Platform-as-a-Service (PaaS) system in a distributed cluster system that can apply modifications to source code. A method of the disclosure includes invoking source-to-image (STI) methodology to execute an instance of an application image. The application image is associated with source code and an application framework of an application. A modification to the source code utilized in the instance is received and identified via the application framework utilized in the instance. The identified modification to the source code is applied during runtime of the instance in a container via the application framework.