What problem does it solve? Building Period-over-Period comparisons in Looker often fails due to LookML extends inheritance clashes, missing surrogate keys on physical tables, and fragile BigQuery bulk loads. This Skill provides the architectural rules and patterns to resolve these failures and deploy a working Customer 360 PoP explore. ## Core Features & Use Cases - Dynamic Surrogate Key Hashing: Compute SHA256-based customer_hash dimensions in LookML when physical BigQuery tables lack hash columns, avoiding Unrecognized name SQL errors. - Extends Clash Resolution: Rules for structuring current_metrics and comparison_metrics views so Looker does not discard base view dimensions when extending PDTs. - PoP Explore Architecture: A semantic join pattern using base_customers, date_config parameters, snapshot joins, and comparison_rules for delta and percentage calculations. - Deployment & Data Loading: Looker SDK production deployment flow and a subprocess-based bq load pattern for resilient NDJSON ingestion. - Use Case: A data engineer building a Customer 360 dashboard needs to compare current versus prior-period account metrics; this Skill guides the LookML structure, key hashing, and BigQuery snapshot loading end to end. ## Quick Start Ask the AI to design a Looker Period-over-Period explore for customer snapshots on BigQuery with dynamic surrogate key hashing and delta measures.