We are developing a Progressive Web App (PWA) as the foundation of a future white-label solution for fitness & health clubs. The complete project will be executed in 3 steps. Step 1 (this contract): Core design, backend, frontend, user roles, profile management, and chat functionality. Step 2 (future contract): Approximately 70% of the remaining feature set. Step 3 (future contract): The last 30% (recipes, community feed, white-label scaling, advanced automations). This job post covers Step 1 only. If the collaboration is successful, Step 2 and Step 3 will follow. Important: All development work must be executed on our server environment. Timeframe: Step 1 must be completed within 1 week (7 days). Step 1 – Scope (this contract) The objective of Step 1 is to deliver a stable, functioning foundation of the application with a professional design, roles & authentication, menu/navigation, user profile management, and a chat system (AI-stub + manual override). Deliverables in Step 1 1. Design & Layout Style: Clean, minimal, Apple-inspired design. Theme: Dark-first (primary color black #0A0A0A), with one secondary accent color. Typography: Modern, highly readable (Inter or similar system font). Usability: Mobile-first design, responsive, PWA-ready. Navigation: Mobile: Bottom tab navigation (Home, Profile, Chat). Desktop: Sidebar navigation with icons + labels. 2. Authentication & Roles Implementation of 3 user roles: User (customer) Trainer Admin Authentication with email + password (prepare option for magic link login in future). Role-based access control (RBAC) with restricted views and permissions. Admin can manage users and assign roles. 3. Menu & Navigation Menu prepared for future modules, but in Step 1 only: Home/Dashboard (basic welcome page). Profile (user’s own data). Chat (central communication hub). 4. User Profile Each User has a personal profile with: Basic information (name, age, gender, membership status). Personal goals (simple text fields). Profile can be edited by the Admin/Trainer. Prepared for extensions in Step 2 (anamnese, training plans, etc.). 5. Chat Functionality (core of Step 1) User → System Chat: Users can send messages through a chat interface. AI-based Stub: Automatic replies generated from predefined text templates. Replies must be delayed by a random interval of 10–30 minutes (to simulate real AI processing). Manual Override (Trainer/Admin): Admin/Trainer can take over and answer instead of the AI. Admin decides whether reply is from AI or Trainer. Conversation Archive: All chat histories are saved. Chats are visible to Admin and Trainer in their dashboard. Technical Environment Frontend: React, Next.js, Tailwind, TypeScript Backend: Node.js, Prisma, PostgreSQL Auth: NextAuth (or similar) Deployment: Docker-based (our environment will be used) Development Rule: All work must be executed directly on our server (we will provide secure access). No local-only development – repository and deployment are managed on our infrastructure. Requirements for the Freelancer Proven experience with React/Next.js/Tailwind (design + frontend). Strong backend knowledge with Node.js, Prisma, PostgreSQL. Experience with RBAC (role-based access control). Experience building chat systems (delay logic, manual overrides, archives). Ability to deliver clean, modular code for long-term scalability. Must respect server-based development requirements (work on our infrastructure). Fluent English or German communication. Timeline Step 1 timeframe: 1 week (7 days) maximum. Daily updates required (short stand-up style report). All code must be fully functional, tested, and deployed on our server within the deadline. Budget & Payment Payment on milestone basis: Milestone 1: Design + Auth/Roles complete (30%) Milestone 2: Profile + Navigation ready (30%) Milestone 3: Chat system functional (40%) Payment release only after deployment & testing on our server. Acceptance Criteria Step 1 Apple-inspired black theme implemented, responsive design. Working authentication system with 3 roles (User, Trainer, Admin). Navigation/menu structure implemented (Home, Profile, Chat). User profile page functional (editable by Admin/Trainer). Chat system: AI-stub with delayed replies (10–30 min). Manual override possible by Admin/Trainer. Conversation archive available. Fully functional on our server (Dockerized deployment).