The connector is easy to switch on and easy to regret. These are the failure patterns we are called in to unpick most often.
1. No agreed source of truth per field
Bidirectional sync without ownership rules means the last edit wins, and nobody can explain why a job title changed overnight. Decide field by field which platform is authoritative, and set the rest to one-way.
2. Two incompatible lifecycle models
HubSpot lifecycle stages and Salesforce lead status often describe the same journey in different words. Map them explicitly, and pick a single definition of 'qualified' that marketing, sales and the board all use.
3. Syncing dirty data at scale
Turning the connector on over an unclean database copies the mess into a second system and doubles the cleanup cost. Deduplicate and normalise first, then sync a controlled subset before opening the gates.
4. Ignoring picklist and required-field mismatches
A required Salesforce field with no HubSpot equivalent produces silent sync errors that sit in a log nobody reads. Reconcile picklist values and required fields during design, and put someone's name against monitoring the error queue.
5. No reporting owner after go-live
Attribution reporting spans both platforms, so it belongs to one person. Without that ownership, teams build competing dashboards and trust in the numbers collapses within a quarter.