Skill-based matchmaking (SBMM) is a critical component in modern online gaming, designed to pair players of similar skill levels to ensure fair and engaging gameplay. Utilized in popular competitive games, SBMM analyzes player performance metrics like win rates and kill/death ratios to create balanced matches, fostering an environment conducive to improvement while keeping the experience thrilling. The system relies on invisible ranking mechanisms such as ELO or MMR to evaluate player skills, creating matchmaking pools that consider factors like latency and geolocation to ensure smooth gameplay. Scalability is key to SBMM's success, requiring efficient data handling, algorithm optimization, and cloud infrastructure to manage player queues and real-time updates. Although SBMM aims to enhance player retention by ensuring competitive integrity and engagement, poorly implemented systems can lead to frustration by creating imbalanced matches. Advanced features like dynamic adjustments and cross-platform matchmaking can further optimize engagement, but challenges like balancing fairness and wait times persist. Tools like PubNub and AWS GameLift support SBMM by providing the infrastructure for real-time data handling and scalable matchmaking solutions, enabling developers to build systems that enhance the gaming experience and drive player engagement.