Use this skill for any GTM Engineering work in Deepline — prospecting, list-building, account research, contact enrichment, email/phone/LinkedIn lookup, ICP qualification, lead scoring, outreach copy, CSV-driven row work, and verifying enriched data. Triggers on phrases like 'enrich this CSV', 'find contacts at these companies', 'build a TAM list', 'waterfall emails for these leads', 'detect job changes', 'is this data accurate', 'write a sequence for', and on any request that mentions Deepline, plays, or named GTM providers (Crustdata, Hunter, Dropleads, etc.). Use this even when the user does not explicitly say 'GTM' — most CSV-with-leads tasks and most provider-driven enrichment tasks are GTM tasks. SKIP only when the request is a Clay table extraction (use clay-to-deepline) or has no Deepline / outbound / data-enrichment dimension at all.