Carrefour France bypassed the traditional pilot phase, migrating its full enterprise scope of 3,000 KPIs and 1,000 users to a universal semantic layer on BigQuery. By focusing on query-cost optimization and co-developing a custom Google Sheets connector, they matched the efficiency of legacy systems while gaining modern flexibility. This session explores the technical rigour behind this “Day 1” scale and how it now powers Carrefour’s production-ready conversational AI agents for Finance and Merchandising.