Combine Patterns

Overview

Combine remains embedded in massive production codebases — UIKit delegates, NotificationCenter bridging, KVO observation, and @Published properties are everywhere. New code prefers async/await, but interop and maintenance of existing Combine pipelines is daily work. This skill covers the decisions and pitfalls that matter: when to use Combine vs async/await, how to avoid memory leaks, and how to bridge between the two paradigms.

Core principle: Combine is not dead — it's mature. The question isn't "should I use Combine?" but "is Combine the right tool for THIS specific data flow?"

When to Use This Skill

• Working with existing Combine pipelines
• Deciding between Combine and async/await for a new data flow
• Debugging AnyCancellable memory leaks or silent pipeline failures
• Using @Published or ObservableObject
• Bridging Combine publishers with async/await code
• Working with Subjects (PassthroughSubject, CurrentValueSubject)

When NOT to Use This Skill