Full-Stack Developer for StonePassport Platform

We are looking for a Full-Stack Developer (or small agency) to build StonePassport, a compliance-focused web and mobile platform for the recycled construction aggregates industry. The system tracks material batches from the lab to the job site via "Material Passports" and QR verification.
​2. The Core Workflow
​Lab Upload: Technicians upload CSV/Manual lab results.
​Automated Flagging: A rule-based logic engine checks data against pre-defined industry specs.
​Geologist Approval: A dedicated review screen for specialists to verify and sign off on data.
​Passport Generation: System generates a secure, public-facing PDF "Material Passport."
​On-Site Verification: A mobile app for contractors to scan batch QR codes and view the live status of the material.
​3. Required Tech Stack
​Web: React or Next.js (Admin/Geologist Dashboard)
​Mobile: React Native (iOS & Android QR Scanner)
​Backend: Node.js or Python (FastAPI/Django)
​Database: PostgreSQL
​Infrastructure: AWS, Vercel, or Heroku
​4. Deliverables & Scope
​UI/UX Design: User flows for 3 roles (Lab, Geologist, Admin).
​Development: Full-stack build of web and mobile components.
​Testing: Unit testing for the logic engine and UAT for the QR scanner.
​Deployment: Fully configured production environment.
​Maintenance: 3 months of post-launch technical support.
​5. Ownership & Terms
​IP Ownership: 100% transfer of all source code, assets, and documentation upon final payment.
​Budget Type: Fixed-price preferred.
​Timeline: Please provide an estimated sprint schedule for an MVP.
​6. How to Apply
​Please share:
​Examples of B2B dashboards or compliance/logistics apps you’ve built.
​Experience with PDF generation and QR code integration.
​A rough monthly hosting estimate based on low-to-medium initial traffic.