Quick Answer: Audit logs in a CRM should be immutable, timestamped, and field-level, capturing who changed a lead record, what changed, when it changed, and ideally from which system or workflow the change originated. To make them operationally useful, design them as a versioned change history rather than a simple activity feed, with diffed before/after values, role-aware access controls, and query performance that supports compliance review, debugging, and pipeline forensics.
A well-designed CRM audit log should function as a complete historical ledger for lead-record evolution, not just a chronological list of edits. Each entry should record the actor identity, timestamp, source context, affected object, changed fields, previous values, new values, and the trigger path whether it came from a human user, API integration, automation, or AI workflow. The log must be append-only and tamper-resistant, with retention policies that satisfy compliance requirements while preserving enough granularity to reconstruct the full lifecycle of a lead. For enterprise use, the audit model should support field-level diffs, relationship changes, soft-delete tracking, exportable evidence, and efficient filtering by lead, user, date range, and event type so teams can diagnose data issues, enforce accountability, and verify process integrity at scale.