Why Testing in Production and how?

"While testing early in the pipeline (i.e., shift-left testing) is necessary and highly encouraged, it's simply not enough on its own.
By testing in production, you build another level of confidence in releases after performing various checks in a live production environment. Testing in production allows the company to see how an application reacts to newly pushed code changes in the wild. It should become a significant component of your future application quality strategy going forward."