How We Built The Deals Tab in Swift UI

Summary

Etsy’s App Updates team rebuilt the long-standing Updates tab as Deals, a destination for coupons and sales, while targeting an October launch ahead of Cyber Week 2023. The team chose Swift UI and Tuist to create a modular, preview-driven implementation rather than extend legacy Objective-C and server-driven layout code. The screen is assembled from typed API modules, parsed with Decodable, and rendered in a Swift UI List using reusable components such as buttons, headers, footers, and listing cards. To bridge incompatible legacy listing-card code, the module accepts a view builder from the UIKit hosting controller, allowing existing cards to be wrapped while newer cards could be implemented in Swift UI. After three months, Deals shipped ahead of deadline; new modules took one sprint or less, previews decoupled front-end work from API support, and the tab increased session conversion and app visits after its mid-October rollout.

Takeaways

1. 1

   Moving the Deals work into a Swift-based Tuist module made Swift UI previews nearly instant and kept app recompilation fast when changes stayed within the framework.

2. 2

   Typed module responses and Decodable parsing made module handling clearer, while reusable components supported additions such as optional footers without anonymous component-based models.

3. 3

   A UIKit-provided listing-card view builder preserved access to legacy cards, preventing Swift UI implementation unknowns from blocking the deadline and later enabling partial migration to native Swift UI cards.