I need an n8n workflow that watches for upcoming appointments created in Google Calendar or Calendly, then automatically pushes a WhatsApp reminder to the client. My preferred path is to keep the whole logic inside n8n; you can decide whether the actual WhatsApp hand-off happens through Twilio, WATI, or the Cloud API as long as the flow stays stable and cost-effective. The reminder content must always include: • the client’s name • the appointment date and time • location details whenever they exist After each send, the workflow should write a log entry to either a Google Sheet or a lightweight database (open to your suggestion). If a message errors out, an alert needs to reach the admin immediately by email or Slack. Deliverables • Fully tested n8n workflow file(s) ready to import • Clear setup notes covering any environment variables, webhook URLs, or WhatsApp configuration steps • A short loom or screenshot walkthrough showing the flow in action and the log being populated Acceptance criteria 1. Events added or rescheduled in the calendar trigger exactly one timely WhatsApp reminder. 2. The three data points above appear correctly in every message. 3. All sends (success or failure) are captured in the log with timestamp and status. 4. Failed sends produce an instant admin notification. When you reply, please attach or link to at least 3 previous n8n automation you have built so I can gauge fit and code style.