I helped redesign a large BigQuery-based enterprise data warehouse and cut spend by 57%. The biggest savings didn't come from dashboards or one-off query tuning. They came from architecture decisions — partitioning, clustering, incremental MERGE patterns, and a better capacity model. Here's how I approach cost as an architectural problem in large systems. The Problem I joined as the Solution Architect for a Fortune 500 financial company running BigQuery at scale — hundreds of analysts, dozens of