SYNC addresses the phenomenon of collective effervescence—the sudden, vivid sensation of boundaries dissolving and energy overflowing when people gather, move, and make sound together. Recognizing that while Gen-Z frequently experiences these powerful collective emotions in group settings, there are currently no tools to make them visible, my team designed a product to shift wellness tracking from the individual to the collective. SYNC is an app and wearable system that visualizes the real-time synchronization of emotional energy, heart rates, and movement within a social circle. The user experience moves through five distinct stages: Check In to map live group data as the night peaks; Reflect to review physical receipts like body temperature, sound, and emotional spikes; Relive to recall exact moments when the group's hearts raced together; Learn to identify which people and spaces allow the user's nervous system to thrive; and Continue to build a clearer picture over time. Ultimately, SYNC serves as a tool to help Gen-Z intentionally navigate their social environments, transforming biological data into a shared medium for cultivating deeper human connection.