Apollo.io is built around a proprietary data network of 230M+ contacts and 30M+ companies, continuously refreshed for accuracy and compliance (GDPR, SOC 2, CCPA, ISO/IEC 27001, PCI DSS). The platform exposes its capabilities via a robust API and an Apollo MCP (Multi-Channel Platform) layer, enabling programmatic access to contact data, sequencing, enrichment, and workflow automation. It integrates natively with Salesforce, HubSpot, and other CRMs, syncing contact records, activity history, and campaign data bidirectionally. The AI Assistant layer powers features such as pre-meeting research briefs, call summaries, follow-up generation, anonymous visitor identification, and real-time form enrichment.