The problem
An export-oriented industrial manufacturer (~200–300 clients worldwide, machines from €15k to €150k) was managing its entire commercial pipeline through an Excel file on a local server, with leads landing across a WordPress contact form, WhatsApp, and a shared inbox. Volume was irregular, two to five leads per week, sometimes none, but every lost lead represented potentially hundreds of thousands of euros.
The constraints were the interesting part: a Microsoft 365 Family account (not Business), an external IT provider with the keys, an owner reluctant to share the Excel file because it contained sensitive pricing and projections, and a two-person commercial team with zero appetite for "learning a new tool".
Our approach
We started by mapping the workflow on a single page, what comes in where, who touches it, where it dies. Then we proposed three architectures: Light, Medium and Heavy, with explicit pros, cons, and costs.
- Light, leads centralised in Airtable, pre-drafted follow-up emails the team can edit and send, simple dashboard. No infrastructure changes. Three weeks.
- Medium, local agent syncing Excel ↔ Airtable, WhatsApp Business API, automated social & competitive watch. Four to eight weeks after Light.
- Heavy, full M365 Business migration, SharePoint, CRM-grade infrastructure. Recommended against: oversized for the lead volume, and would block on the owner's reluctance to migrate.
The senior call: we recommended Medium, but starting with Light. The point wasn't to sell the biggest project, it was to ship something useful in three weeks without breaking what already worked.
What we shipped
Phase 1 (Light), centralised lead intake, pre-drafted follow-ups triggered by date, and a dashboard the owner can read on his phone. Built without touching the local Excel file or the IT provider's setup.
Phase 2 (Medium), a local sync agent keeps Excel and Airtable in lockstep so the owner never has to share the master file. WhatsApp Business API replaces the team's personal numbers. A weekly competitive watch surfaces relevant content in FR / EN / ES.
Stack
Why it works
The architecture respects the constraints the client actually has, not the constraints a textbook would prefer. The owner keeps control of his data. The IT provider is not put on the critical path. The team gets a tool that follows the workflow they already have, instead of the other way round.