I have developed an android application on food delivery where I have used Firebase to store and retrieve data. I wanted to implement collaborative filtering algorithm on my dataset and I am stuck on how to begin. For now I am using an excel sheet where I have inserted my values. I am using openCSV to read and write rating values in my dataset. Now the main thing is how can I implement collaborative filtering on this dataset. Any thoughts on what can be the most effective way to proceed? I have been thinking a lot on this but I am failing at one or the other step and because of that I am unable to proceed. Any ideas or suggestions is really helpful at the moment.