Still open: getting people into the cart in the first place. Reached-checkout rate dipped slightly even as everything downstream improved - proof that this problem now lives earlier in the funnel than the cart itself. It's a systems and flow problem, not a component one, and it's the next thing I'd solve if I kept iterating.

Still open: scalability. This project taught me, concretely, how many parts of a business a single component like a cart actually touches. It's not an isolated interface — it's a chokepoint every customer passes through. Handing this off responsibly means making sure there's no margin for a kink or bottleneck as the business scales past what I can personally watch over.

The bigger shift this project caused in me goes beyond the cart itself. For a while, I thought of UX and design, web design - as something you use to enhance business, something you design around business. Now I understand that design is the business. The UX of the site is the store. My background in media theory and HCI taught me about interfaces, that the interface you're given is how you perceive the world, how you perceive reality. So the interface people are given for a site is how they come to think of the brand. Just like the cart, the entire process and function of any company needs an interface that delivers - one that's accessible, intuitive, and a true reflection of the kind of organization you are.

That's not a design principle I'm reciting. It's the actual mechanism behind every number above.