Built an automated invoice workflow using n8n, Google Sheets, Gmail, Google Drive, and HTML-to-PDF. The workflow captures invoice data from Google Sheets, cleans and processes the data, generates an invoice in HTML, converts it to PDF, stores the PDF in Google Drive, and automatically sends the invoice to the customer by email. It also includes a customer-check and error notification flow to handle missing customer information. Tools: n8n • Google Sheets • Gmail • Google Drive • HTML-to-PDF