As Chad writes, you can implement the logic you require by using almost any language. We use server based Node to manage Janus. We do not use MongoDB or something like that. We use XML-files for a practically similar purpose.
But in any case, you can easily implement the logic by using JavaScript in Node, PHP, Python, C(++), etc. Just store the configuration in the way you want. Then start your management program. The management program reads and manages the configuration files/database. The management program interacts with Janus by using the APIs (we use the HTTP-interface) and changes the configuration in the way we want. Much, much easier than changing the code of Janus.