A product mindset asks why. An engineering mindset asks how.
'Why' should always come first followed by 'How', followed by 'Why' again. How much time do we spend on each of these buckets determines how robust and relevant our product is going to be.
Too often, we focus on the why without too much understanding on how, and we come up with a product that is hard to implement. On the other side, if we spend too much time on the how, we fail to implement something that can provide feedback on the why.
Personally as a rule of thumb, I love to spend a week on why, looking at data and putting together quickly testable user flows and designs, and then spend few weeks on how. The aim is not to build the best product, but to validate our hypothesis. Then, come back to the why.
Combining product and engineering mindset is the key to building something that is robust and reliable.