A CRM's automation layer, migrated to V2 and extended

Problem

The CRM's automation layer ran on modules the platform was retiring, with no migration path tested yet, while the team also wanted follow-up sequences and mailing-list syncs added without breaking anything already moving leads through the pipeline.

What I built

• Migrated all 12 Make scenarios off the CRM's deprecated V1 modules to V2, one at a time, with 10 of 10 tests passing before cutover. One old connection is left to retire once nothing else references it.
• An email follow-up sequence engine in n8n running on the CRM, with run manuals and a deal-id backfill script so older deals get sequenced too. Built and documented, waiting on the operator's templates and configuration before it switches on.
• Two daily syncs from Airtable to Brevo mailing lists, diff-only upserts so a contact already synced does not get re-sent.
• A careers-page sync, and a reply radar that watches for replies on outbound sequences.

Result

Every cutover test passed and no lead loss has been reported since. The mailing-list syncs run daily without re-sending anyone. The follow-up engine is ready to go live as soon as the operator supplies templates and configuration.

What it shows

Migrating a live automation layer without downtime, then extending it, takes the same discipline either way: test before cutover, diff before syncing, and document what is ready so someone else can switch it on.