Pattern Parties are a method used by incident.io to maintain consistency in their codebase and keep design patterns up-to-date. During these events, the engineering team dedicates time to implementing a set of related design patterns across the entire codebase. The process involves choosing a theme for each party, selecting impactful patterns within that theme, documenting agreed patterns, and providing guidance on migration. By the end of the Pattern Party, engineers are familiar with the new patterns and can apply them in their work. This approach helps improve shipping speed, smoother onboarding for new joiners, quicker debugging, and better collaboration among teams.