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Data cleanup before literally anything else.
"Let me just quickly dedupe this list" → 2 hrs gone
"I'll standardize these phone numbers real quick" → it's lunch
The groan-inducing part isn't the task itself. It's knowing that you'll do the exact same cleanup next week because the data is still messy.

RevOps teams I've seen use a hybrid approach:
Standard fields for ops use - sales reps see one "Phone" field
Source-specific fields for audit - hidden "ZoomInfo_Phone", "Apollo_Phone" for provenance
Key is waterfall enrichment logic, HubSpot's "Complete if Missing" rule helps prevent overwrites.