Completion of backend and API for mobile app

I have a near-completed backend for a mobile app that needs to be finished and an API built for use by a mobile app (the app is yet to be built) The backend is written using Python, Swift and Java.There are also elements of machine learning. The developer who was working on this project has recently been given a full-time job and as such doesn't have the time to finish the work.

I have the source code and accompanying resources written so far.