Methods, computing systems and computer program products implement embodiments of the present invention that include defining, for a data masking engine executing in a platform as a service (PaaS) based software environment, one or more data masking rules. Upon detecting, by the data masking engine, data processed by a software application executing within the PaaS based software environment and in accordance with a given data masking rule, the data masking engine can perform a data masking operation on the data.