I’m looking for a strong full-stack developer to build a web-based tariff/import duty simulator similar in feel and functionality to Flexport’s tariff calculator https://tariffs.flexport.com/. The tool should allow users to input shipment details (country, transport mode, declared value, etc.) and receive a clear breakdown of estimated duties/tariffs/fees in a clean, interactive UI. Key Features (MVP) Interactive Calculator UI Clean, modern interface (desktop + mobile responsive) Form inputs: origin country, destination country, entry date, shipment value, transport mode, and other relevant fields Real-time updates of results as inputs change Results displayed in a clear breakdown (line items + totals) Backend Calculation Engine API endpoint(s) to process inputs and return results Business logic designed so tariff rules can be updated over time Validation for inputs and safe handling of missing/invalid values Data Source Integration (Discuss Options) Prefer integration with a reliable tariff/duty data source or API If real data is not available within budget, propose a realistic approach (limited dataset, manual upload, admin panel, etc.) Caching to reduce repeated calls and improve performance Deployment Deploy to Vercel/Render/AWS (open to recommendations) Provide clear documentation for setup and future maintenance Tech Preferences (open to alternatives if justified) Frontend: React or Next.js Backend: Node.js (Express/Nest) or Python (FastAPI) Database: Postgres preferred Optional: Docker Deliverables Working web app (MVP) Source code in a Git repo Documentation: setup, deployment, and how to update tariff logic/data Basic tests (at least core calculation paths) Milestones UI prototype + flow (Figma or in-code) Core calculator UI + basic backend endpoints Data integration + calculation logic Final polish + deployment + documentation