N8N Developer for Workflow Automation

We are looking for an experienced automation developer to build an AI-powered outbound calling system for a real estate acquisition business. Project Overview We currently use SignalWire for telephony and want to build a fully automated outbound calling workflow using n8n. The system should: Pull leads from Google Sheets Initiate outbound calls through SignalWire Detect humans vs voicemail using AMD (Answering Machine Detection) Connect live answers to an AI voice agent Leave a prerecorded voicemail when voicemail is detected Update call outcomes back to Google Sheets Log call recordings and call dispositions Support future integration with CRM systems Required Skills n8n workflow development SignalWire Voice API SIP and telephony concepts AMD (Answering Machine Detection) AI voice integrations Webhooks and API integrations Google Sheets API Node.js or Python (if custom middleware is required) Preferred Experience Please apply only if you have previously built one or more of the following: AI calling systems SignalWire integrations Twilio voice applications SIP-based call routing systems Real estate lead generation systems Voice AI agents Deliverables Complete n8n workflow SignalWire call creation workflow AMD workflow (human vs voicemail detection) Voicemail drop workflow AI handoff workflow Google Sheets integration Documentation explaining how to maintain and modify the system Application Requirements Please include: Examples of similar projects Technologies used Estimated timeline Fixed-price quote Any recommendations for reducing per-call costs We are looking for a long-term technical partner who can continue improving the system after the initial deployment.