AI-Powered Lead-to-Customer Automation System | Make.com, HubSpot, Airtable, OpenAI, Calendly

I’m looking for an experienced Make.com automation specialist to build an end-to-end lead-to-customer automation system for my business. Right now, leads, appointments, customer information, and payments need to be handled across different platforms. I want to connect everything into one reliable workflow that can automatically qualify leads, update our CRM, notify the team, schedule appointments, and handle the transition from lead to paying customer. The workflow should include: Lead Capture - Capture leads through a website form/webhook - Validate and clean incoming information - Check for duplicate contacts - Store lead information in Airtable AI Lead Qualification - Send lead information to OpenAI - Identify the service/product the lead is interested in - Generate a short lead summary - Score and categorize the lead as Hot, Warm, or Cold - Recommend the appropriate next step HubSpot CRM - Find existing contacts before creating duplicates - Create or update contacts - Create/update companies where necessary - Create and update deals - Automatically move deals through the appropriate pipeline stages - Store the AI-generated qualification data in HubSpot Automated Lead Routing - Hot leads should trigger an immediate Slack notification and personalized email - Warm leads should enter an appropriate follow-up process - Cold leads should be placed into a nurture workflow - Each lead should be tracked throughout the process Calendly Integration When a qualified lead books an appointment: - Update Airtable - Update the HubSpot contact/deal - Record the appointment information - Notify the appropriate team member - Send a confirmation email Stripe Integration When a customer completes payment: - Match the payment to the correct customer/deal - Update HubSpot - Move the deal to Closed Won - Update the Airtable customer record - Trigger a customer onboarding email - Notify the team in Slack Reliability & Error Handling I don't want a basic automation that works only when everything goes perfectly. The system should include: - Duplicate detection - Filters and routers - Error handlers - Retry logic where appropriate - Failed-record tracking - Manual review for exceptions - Automation logs in Airtable - Timestamps and execution status - Clear handling of API/webhook failures I would also like HTTP/API integration where appropriate, rather than relying only on native Make.com modules. What I'm looking for I'm looking for someone who is comfortable working with: - Make.com - HubSpot CRM - Airtable - OpenAI/API integrations - Webhooks - HTTP/API requests - JSON/data transformation - Calendly - Stripe - Gmail - Slack - Error handling and automation debugging The main goal is to build a reliable, scalable automation that takes a lead from initial contact all the way through qualification, booking, payment, and customer onboarding with minimal manual work. Please share examples of similar Make.com automation systems you've built, especially projects involving CRM, AI, webhooks, APIs, or multi-step business workflows