I have more than 13 years experience in J2EE/Java and 4 years in Android.
In the last 2 years I used to provide machine learning services for companies who deal with real time bidder in adtech. Google analytic and R Languages are my favorite. With those great tools, magic can happened.
I do believe that we should measure everything we do. Since no one knows the future, we should perform A/B testing and to test changes for every change we made against the current design and determine which ones produce positive results.