I'm a backend-leaning full-stack developer. On every project I start with the data model and the API contract, then build the React or Next.js interface on top. That order is why features keep working as the product grows — permissions, payments, money and stock calculations live in one well-tested place, not scattered across components.
For startups, that means an MVP you can actually build on. For agencies, it means a dependable developer who can take a client project from brief to deployment and leave behind code your team can maintain. For product teams, it means someone who can pick up a ticket on either side of the API without a hand-off.