Lottie and Swift at Airbnb
Article Summary
Airbnb rewrote their massively popular Lottie animation library from scratch in Swift. Here's why they chose a complete rewrite over incremental updates.
Tyler Hedrick from Airbnb's iOS team shares the personal and technical journey behind migrating Lottie, the open-source animation library used by over 50% of top apps, from Objective-C to Swift. Written in 2019, this reflects a pivotal moment in iOS development.
Key Takeaways
- Over 50% of top apps now use Swift, but Lottie was stuck in Objective-C
- Hybrid codebases force painful context switching and block modern language features
- Swift's structs, pattern matching, and protocols enable cleaner, more maintainable code
- Newer iOS engineers learn Swift first, making Objective-C projects increasingly inaccessible
- Open sourcing the rewrite early brought immediate community contributions and improvements
Critical Insight
Airbnb chose a full Swift rewrite to future-proof Lottie, reduce technical debt, and make the codebase accessible to modern iOS developers.
