We are seeking a proactive Senior Full-Stack Developer to lead the complete development of a multichannel conversational AI agent. This remote project (freelance/project) aims to create an automated customer service solution with natural interaction, capable of performing tasks such as scheduling, payments, and operational routines via WhatsApp, phone calls (landline/mobile), and other digital channels, optimizing communication and efficiency. The professional will be responsible for the entire architecture and delivery of the solution, from VPS configuration (e.g., Hostinger) with Coolify for deployment and maintenance, to the design of a robust, scalable, and secure platform. Responsibilities include the implementation and customization of n8n for complex workflows, and the integration of Chatwoot (fazer.ai) to centralize customer service. Connecting communication APIs such as WhatsApp (using Z-API, Baileys, or the official API via Twilio) and Twilio Voice for phone calls will be necessary. In the core of artificial intelligence, we will use OpenAI (GPT-4.1-mini); for voice functionalities, technologies such as Whisper for transcription and ElevenLabs for speech synthesis will be employed. Additional integrations include Google Calendar for scheduling, Google Drive for file management, Asaas for payment processing (Pix/boleto), and PostgreSQL for data storage. Essential Requirements: - Proven experience in complex development projects. - Proficiency in TypeScript/JavaScript and Python. - Ability to automate processes with n8n. - Experience with VPS infrastructure and DevOps practices. - Knowledge of API integrations (WhatsApp, Twilio, AI platforms). - Proficiency in relational databases (PostgreSQL). Desirable Skills: - Previous experience developing chatbots or AI agents. - Knowledge of monitoring and logging tools. - Familiarity with good security practices in software development. Application: Please send your resume, portfolio, and a brief presentation highlighting relevant projects that demonstrate your experience in the areas mentioned.