This list mentions A/B testing a few times and it's worth noting that A/B testing is great but it's not free. I've seen a nontrivial number of smart engineers get bogged down in wanting to A/B test everything that they spend more time building and maintaining the experiment framework than actually shipping more product and then realizing the A/B testing was useless because they only had a few hundred data points. Dat…
For a lot of what you want to know the above will give better information than a 100% polished A/B test in production. When people see a polished product they won't give you the same type of feedback as they will for an obvious quick sketch. The UI industry has gone wrong by making A/B in production too easy, even though the above has been known for many decades.
(A/B in production isn't all bad, but it is the last step, and often not worth it)