Making decisions based on subjective feelings that contradict your own experiences erodes motivation. Is not a good feeling. Symptoms of a non-evidence or data based development process are feature creep and the feeling like you never get anything done. How do we get to a place where we can make data-based decisions? In this session. We’ll be looking into different systems to create and build AB-test in your code base. Learn how we can determine if a change has a significant effect. We’ll go into user testing and how that fit in with our AB-strategy. Trying to answer the question of whether you should you focus on qualitative testing or data-driven testing. Working data driven has drawbacks. What happens if the data is wrong or inaccurate? We need strategies on how to test and validate the data to be certain about our decisions.