Hi! This job post caught my eye because I literally just finished building an almost identical architecture for a B2B consulting agency.
I work entirely on self-hosted n8n and my main focus is on system stability and data integrity. Since you already have the logic pre-defined, here is how I would handle your core technical bottlenecks:
Email Classification & Routing: Instead of messy multi-node setups, I use a single-node LLM strategy (OpenAI/Gemini) forcing structured JSON outputs. This makes routing to Slack or forwarding hotel updates completely bulletproof.
Request Status Tracking: The biggest issue with Google Sheets as a database is row duplication. I solve this by using the native Gmail Message-ID as an absolute primary key. Whether it’s Pending, Offer Sent, or Confirmed, n8n will always update the exact correct row.
Auto-Reply Loop Protection: I build strict trigger-level filters (e.g., excluding self-sent emails) and “Bouncer” IF nodes right at the webhook level to ensure auto-replies never trigger an endless loop.
Error Handling: No black-box builds. I set up idempotent nodes with auto-retry, backed by a separate Global Error Handler workflow. If an API request crashes, it instantly pings a Slack digest with the exact workflow and node name.
I’m very comfortable working with your requirements document and can break down the fixed rates per workflow.
Would love to drop you a DM or jump on a quick screen share to show you how the deduplication and error-handling logic works in my current production build! Let me know.