[D] Ways to find a Machine Learning mentor • r/MachineLearning

I am both personally interested in Machine Learning, as well as for my PhD which is loosely related to ML, and as someone working on a startup in his spare time. I often come into situations where I need an expert in Machine Learning to push me into the right direction. But I often cannot disclose my problem publicly (e.g. because my PhD has a project sponsor). What are options for me to get a Machine Learning mentor (an actual expert ideally at the cross section of computer vision / image manipulation and Deep Learning)? How could I set up a basic agreement that I could ask some questions once in a while in exchange for some compensation (monetary or otherwise)?