Client context
A professional services firm was onboarding clients by hand. Intake, document sorting, task updates and customer messages depended on people moving information between tools.
The manual problem
Every new client was opened by hand. Someone took the intake details, sorted the documents that arrived, updated the tasks and remembered to tell the customer where things stood. The work was not hard; it was spread across Slack, email, WhatsApp, Google Drive, Trello and a spreadsheet, and moving information between them was the job.
System overview
I built a suite of 12 workflows across eight integrations.
Workflow path
A sales rep adds a client from Slack. Documents arrive by email or WhatsApp, get classified, and land in the right Google Drive folder, Trello card and checklist. When a sale closes, the customer is notified and the internal tracking updates.
Document intake that routes itself
Someone watched an inbox, opened each attachment, decided which account it belonged to and copied it into the right Trello card.
The workflow reads the email, pulls the attachment, extracts the fields it needs and routes the document. An optional AI step handles messy text that plain rules would miss.
New documents reach the right place automatically, while unclear cases are flagged for review instead of getting lost.
- Retry with backoff.
- Manual fallback queue.
- Service-account authentication.
- Run logs and alerts.
Failure modes
Automation fails quietly, which is the part worth designing for. A workflow can stop without anyone noticing. The same document can arrive twice, once by email and once by WhatsApp. A sync can run into the write limits of the API underneath it. A document can arrive that no rule and no classifier should be trusted to place. Each of those is handled where it happens rather than discovered later by whoever was waiting for the result.
Reliability layer
The system is useful because of the part around the happy path.
- A centralized error handler catches failures and alerts the team in Slack.
- A Files Registry prevents the same document being processed twice across channels.
- Delta writes keep updates inside Google Sheets API limits.
- Secure service-account authentication instead of shared credentials.
- Daily backups and handover documentation support recovery and ownership.
- Unclear cases go to a person.
Result
Manual intake, document routing and customer updates moved into one tracked process across every service line.
Stack
- n8n Cloud
- Slack
- AI document classification
- Google Drive
- Trello
- Google Sheets
- Service-account authentication
Lesson
The part worth copying is not the happy path. What made this system worth keeping is what happens around it: a failure that raises an alert instead of going quiet, a duplicate that is recognised before it is processed, and a document that goes to a person instead of being guessed at.
Related service
Business AutomationHave a process spread across too many tools?
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