The problem isn't that HubSpot, Stripe and Notion don't talk to each other. The problem is that they each talk in three different ways and every change in one propagates to the others a day late, through a different person, and sometimes it doesn't propagate at all.
The golden rule: one source of truth per data type
Before touching integrations, decide which tool is the source of truth for each data type. There can't be two.
- Contact / account / pipeline → HubSpot rules.
- Subscription / payment / billing → Stripe rules.
- Onboarding / project / deliverables → Notion rules.
The flow in four hops
When a deal closes in HubSpot: webhook → create customer and subscription in Stripe → Stripe webhook → create project in Notion with onboarding template → notify Slack. Each hop is idempotent and logs what happened in an events table.
The three most common mistakes
- Using Zapier for everything. Works until it doesn't, and when it fails you don't find out.
- No event log. When something breaks, you don't know where to start.
- Two-way syncing. If all three write to each other, grab the popcorn.
