Next.js Customer Portal Build

I need a skilled React / Next.js developer who can turn a structured JSON UI spec into a production-ready customer portal. The project covers the full flow—from OTP authentication to data-driven screens—using Tailwind CSS and shadcn/ui components styled with the custom design tokens I will supply. No Figma files are coming your way, so you should be comfortable working directly from tokens, the JSON spec, and written UX guidelines.

Core scope
• Implement an OTP login route that sends, verifies, and maintains the session.
• Build the app shell with top navigation (Dashboard, Usage, API Keys, Billing) and set up Next.js routing.
• Create four fully functional pages:
– Dashboard: KPIs, charts, and tables fed by REST APIs.
– Usage: filter controls plus a usage-by-endpoint table.
– API Keys: create and list keys, also via REST.
– Billing: plan details, invoices, and payment methods.
• Wire data loading to the REST endpoints defined in the spec, handling loading, empty, and error states gracefully.
• Ensure the UI is fully responsive and matches the provided design tokens.
• Deliver clean, maintainable TypeScript code with clear component boundaries.

Deliverable
A ready-to-deploy Next.js application (latest stable version) that passes QA with the following acceptance criteria: OTP flow works end-to-end; navigation never requires a full page reload; each screen shows real data from the mocked or live REST endpoints; the styling honors our tokens; and no eslint or TypeScript errors remain.

Clear, frequent communication is important to me, so please be comfortable sharing progress updates and asking questions early. If you have deep experience with Tailwind, shadcn/ui, and REST-driven SaaS dashboards, I’d love to hear how you would approach the build and an estimated timeline to ship.