Building a scalable design pattern library involves creating a system that supports design consistency across projects while facilitating collaboration among team members. Key steps include defining a clear structure, documenting guidelines, and ensuring easy access to components for designers and developers. This approach not only enhances efficiency but also fosters a cohesive user experience.

Design pattern libraries often face issues such as inconsistency, outdated documentation, and lack of user involvement, which can hinder their effectiveness. To create a successful library, teams should prioritize collaboration, maintain regular updates, and ensure comprehensive user feedback to address these challenges.