AI Agent Developer Needed for Appointment Booking and Payment Automation Platform

Job Description We are looking for an experienced AI/automation developer to build a reusable conversational agent that can book appointments, collect payments, and integrate with different third-party systems through APIs. The solution should not be limited to one industry. It should have a modular, API-first architecture so it can be configured for healthcare, beauty, consulting, home services, restaurants, professional services, and other appointment-based businesses. The agent should be capable of communicating with customers, checking real-time availability, booking or rescheduling appointments, collecting required customer details, processing payments securely, and sending confirmations and reminders. Core Features AI-powered conversational booking flow Check real-time staff, service, and location availability Book, reschedule, and cancel appointments Support multiple services, employees, locations, and time zones Collect customer information and custom booking questions Calculate service prices, deposits, taxes, and discounts Generate secure payment links or payment sessions Confirm payment status before finalizing appointments Send booking confirmations and reminders Handle common customer questions Escalate conversations to a human when required Maintain conversation, booking, and payment logs Admin configuration for business rules and integrations Integration Requirements The platform should support integration through REST APIs, webhooks, and reusable connectors. Initial integrations may include: Google Calendar and Microsoft Outlook Calendly or similar scheduling platforms Stripe, PayPal, Square, or other payment gateways CRM and ERP systems Custom booking platforms Email, SMS, WhatsApp, web chat, or voice systems Zapier, Make, or n8n where appropriate We understand that no solution can automatically integrate with every system without configuration. The goal is to create a standardized integration layer that makes adding new systems fast and manageable. Technical Expectations Secure and scalable backend architecture OpenAI, Claude, Gemini, or another suitable LLM Function calling/tool calling for reliable actions Structured workflows rather than relying only on free-form AI responses Authentication and role-based access API key and credential management Webhook handling and retry mechanisms Time-zone and daylight-saving support Idempotency to prevent duplicate bookings or payments Proper error handling and audit logs PCI-conscious payment implementation without storing raw card details Documentation for adding new integrations Deliverables Technical architecture and database design Working MVP of the AI booking and payment agent Calendar and payment integrations Reusable connector or adapter framework Admin configuration interface API and webhook documentation Testing and deployment Source code and setup instructions Ideal Candidate Strong experience with AI agents and LLM function calling Experience building appointment-booking systems Experience with Stripe or similar payment APIs Strong Node.js, Python, or equivalent backend experience Knowledge of webhooks, OAuth, REST APIs, and third-party integrations Experience with conversational workflows, chatbots, or voice agents Ability to design a reusable multi-tenant architecture Strong understanding of security and payment compliance Please include relevant examples, your recommended architecture, development timeline, estimated cost, and the integrations you recommend for the first MVP.