The proliferation of personal health awareness has accelerated the consumer demand for comprehensive fitness and lifestyle management platforms. However, the current digital health ecosystem remains fragmented, requiring users to navigate separate isolated applications for gym schedules, dietary tracking, specialized workouts, and subscription payments. This operational compartmentalization introduces data siloing and severe administrative friction for facility operators. To resolve these inefficiencies, this paper introduces the architectural design, algorithmic formulation, and empirical evaluation of YourCare, an enterprise-grade, full-stack management ecosystem developed using the MongoDB, Express.js, React.js, and Node.js (MERN) paradigm. YourCare delivers a unified platform that integrates granular member tracking, automated biometric evaluations, dynamic level-based workout matrix generation, precision macronutrient dietary planning, and asynchronous payment tracking into a single responsive system. Deployed with cloud- based multi-media asset pipelines via Cloudinary and secured with JSON Web Token (JWT) state abstraction and bcrypt-based cryptographic hashing, the platform optimizes operational workflows for health clubs while rendering real-time, dark/light adaptive interfaces to end-users. Technical evaluation profiles indicate that YourCare effectively manages thousands of concurrent transactions, executing debounced search filtering in sub-45 milliseconds and maintaining complete operational data sovereignty.

Keywords— Full-Stack MERN Architecture, Gym Management Systems, Software Engineering, Database Normalization, Automated Biometrics, Dietary Scheduling, Operational Efficiency.