If you haven't yet bought a mattress online, it's kind of a magical experience. A box arrives at your door that's roughly the size of a large suitcase. You open it up, unroll the contents onto the floor, and about an hour later you have a complete mattress.
Great care has obviously been taken to design a terrific end-to-end experience: from a limited selection online, to the compressed packaging described above, to the generous return policies these companies tend to have.
However, the core part of the experience — the compressed mattress delivery — is an elegant collaboration between engineering and design. At some point, engineers came up with the idea of compressing mattresses into tiny containers, and then worked with designers to create a system and business around this idea.
This is a helpful reminder that great designs are typically a collaboration between designers and other fields. I'm suspicious of any project plan that has design work happen upfront, to be followed by engineering efforts, because this artifically constrains what's possible.