ButfitSeoul, a fitness technology company founded in 2018 in South Korea, has successfully modernized its platform architecture to address the challenges of delivering fast, reliable, and personalized user experiences amidst rising user traffic and infrastructure costs. Initially relying on a legacy RDBMS architecture, ButfitSeoul faced difficulties in supporting peak-time traffic and real-time data synchronization, particularly for offline functionality in gyms with variable connectivity. To overcome these issues, the company adopted Couchbase as its core data platform, deploying it on Amazon Web Services (AWS) to enhance flexibility, scalability, and reliability. This transition enabled ButfitSeoul to significantly reduce API calls, improve app load times, and enhance user interface responsiveness, while also lowering operational costs and simplifying DevOps processes. As a result, ButfitSeoul now offers a seamless, gamified fitness experience that integrates physical workouts with a mobile app, rewarding users for staying active and engaged.