A global sportswear brand successfully migrated their ecommerce platform from Salesforce Commerce Cloud's monolithic design to a headless approach using Next.js, achieving significant performance improvements without disrupting their core business. The migration strategy involved choosing the right frontend framework, planning for incremental traffic management, ensuring business continuity, and utilizing technical strategies such as Edge Middleware, server-side rendering, and Incremental Static Regeneration. This approach enabled them to unlock a new level of performance, halve load times, cut cart abandonment by 28%, and increase mobile conversion rates by 15%. The team's productivity improved with reduced deployment and rollback times, and they saw a 40% improvement in development team retention. The business impact was also positive, resulting in $10M in incremental quarterly online sales and zero downtime during high-traffic periods.