It may be helpful for you to approach this by breaking down the problem into it's component parts and starting from the product and user. When I was interviewed regarding a similar broad question, here's how I broke up the problem and tackled them:

• What is the current goal of the product? ** Primary - e.g. Allow users to learn about the product and easily add to cart, increase same session conversion ** Secondary - e.g. Surface additional products that she may aslo be interested in buying - increase the number products to be added to the cart

• What problems do the product currently face? e.g.: ** Unclear user flow ** Primary purchase CTA is unclear ** Unoptimized mobile-web design ** Lack of additional product merchandising

• Make educated guesses to current problems. E.g.: ** User Increase user engagement Increase conversions

• How would I solve the problem? ** User journey ** User personas ** Wireframes ** Applying UX best practices ** Propose ab testing

• Proposed iterative improvements ** Changes to design to make the process easier and cleaner

• Big bold ideas ** Big bets that are hard to do but could net big wins

• How would I implement solutions? ** Wireframes of small proposed changes that gets quick wins ** Wireframes of a long term vision for the page

• What could be some technical challenges that prevent your designs from happening? ** Takes some educated guesses on why the changes you're proposing have not happen or may not happen (be objective)

• How to valid solution ** User testing ** AB testing

• Metrics ** How do you measure if your proposal is successful

Good luck!