Rebuild our SaaS analytics dashboard in Next.js + TypeScript

We run a B2B analytics product and our dashboard is a jQuery-era mess. We want it rebuilt in Next.js (App Router) with TypeScript, Tailwind and a clean component library. Data comes from a PostgreSQL warehouse through a small REST API that already exists. You'll own the front-end: charts, filters, saved views and CSV export. We'd like weekly demos and small pull requests. Bonus if you've shipped billing or usage-metering screens before.