This is a section from a video I did for O'Reilly back in 2015 called Data Driven Products . I think it's pretty good as a standalone set of case studies of how you might go about making changes to a web product if you care about not totally screwing up.
If you like this you might also want to look at Data Driven Products Now! , which explains how you'd go about using data to inform the product discovery phase.
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