Product-Market Fit - Feature Set & UX

We will have a group discussion about the 4th and 5th levels in Dan Olsen's Lean Product Pyramid - "Feature Set & UX". Once we have determined our value proposition, how do we proceed with defining a feature set and a great user experience?

Come with questions or with experiences or resources to share.

Here's a link to learn more about the pyramid: https://www.mindtheproduct.com/the-playbook-for-achieving-product-market-fit/