CloudTrail's S3 + Athena pattern is powerful but has friction. Building Athena tables, setting up partitions, writing queries, and interpreting results consume time when audits are urgent. CloudTrail Lake removes this friction. It stores event data directly in a dedicated lake and runs SQL instantly from the console. Today, from the SOA operator's perspective, we dive deep into Event Data Store design, SQL query patterns, how ML-based Insights detects anomalies, cross-account usage at organizational scale, and practical implementation.