In fashion school, you learn a very specific discipline: start with a concept strong enough to hold a whole system together. Not just a single piece, but a line, a collection, a brand: things that need to work together across dozens of variations.
From there, you build prototypes. You test them. And then comes something called grading: scaling your pattern across all sizes. And here's what nobody tells you before you do it: what works in a size 8 doesn't automatically work in a 16. You can't just scale the numbers. You go back to the pattern, you adjust, you test again. It's systematic iteration, fix the system, not the individual case.
Then comes handoff. Technical specs for production: cut sequences, material quantities, size breakdowns, pattern layouts optimized to reduce fabric waste. If the specs aren't airtight, costs blow up, production slows, quality falls apart. Good design means nothing if it can't be built reliably at scale.
When I moved into product design, I realized I'd been doing this all along, just with garments instead of interfaces.