For a translation firm, every email and web form is classified, matched to the client record and turned into a drafted quote, with a hard check that stops a wrong number before it ever reaches a customer.
What I built
A production system that handles the full first-response lifecycle for a company receiving a high volume of client document requests: it classifies inbound email and web-form enquiries, files attachments, updates a live CRM ledger, and writes ready-to-send replies for human review. Built as two coordinated workflows, a 224-node email pipeline and a 38-node web-intake pipeline, sharing one CRM, one document store and one set of business-rule documents.
Architecture: eight reasoning paths behind a three-layer safety net
Each AI call is narrowly scoped and schema-constrained. The final gate is deliberately not a model, so a bad draft can be stopped by logic rather than by judgment.The live email workflow, zoomed out: 224 nodes across eight reasoning paths, fanning out from a single intake and converging on one drafting and compliance path. Node labels are illegible at this scale by design, the point is the shape.
Design decisions
Eight separate reasoning paths, each with its own tightly scoped model call, instead of one large catch-all prompt
Business rules live in an editable reference document the AI layers read at runtime, so staff can change behaviour without a deployment
Thread-aware state matching across mailbox and CRM, so a reply three weeks later still lands on the right record
Production engineering
Root-caused and fixed an infinite-retry loop, a JSON-injection bug from unescaped input, and a lifecycle gap that could have billed a client twice
Direct API-level integration work to guarantee correct message threading in cases the standard connector could not handle
Result
Live in production on a real client inbox, with a phased rollout planned across the company's remaining mailboxes.
Under the hood
n8n · Microsoft Graph, Outlook and OneDrive · GPT-5-class models