TL;DR — Tinder Matching

Design Tinder's location-based matching system — a card stack interface where users swipe right (like) or left (pass) on profiles, and a mutual right-swipe creates a match that unlocks messaging. The system serves 75M monthly active users and must generate a personalized stack of nearby profiles ranked by compatibility, attractiveness, and activity level — all within a few hundred milliseconds of the user opening the app. Key features: Swipe right (like) or left (pass) on profile cards. Mutual right-swipe creates a match and unlocks chat.