--- title: Interview with Donal O'Brien - We measure developer... description: An interview with Donal O'Brien, a Core Clients engineer at SoundCloud, discussing how the iOS team scaled its app architecture. Topics include the migration... canonical: https://daily.dev/posts/interview-with-donal-o-brien---we-measure-developer-build-times-so-that-we-can-measure-improvements--oil0nvhbd twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Interview with Donal O'Brien - We measure developer build times so that we can measure improvements and regressions | daily.dev og:description: An interview with Donal O'Brien, a Core Clients engineer at SoundCloud, discussing how the iOS team scaled its app architecture. Topics include the migration... og:url: https://daily.dev/posts/interview-with-donal-o-brien---we-measure-developer-build-times-so-that-we-can-measure-improvements--oil0nvhbd og:image: https://api.daily.dev/og/posts/OIL0NvHbD.png og:image:alt: Interview with Donal O'Brien - We measure developer build times so that we can measure improvements and regressions og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Interview with Donal O'Brien - We measure developer build times so that we can measure improvements and regressions **[ Tuist ](https://daily.dev/sources/tuist-blog)** · 6 min read · 0 upvotes · 0 comments ## Summary An interview with Donal O'Brien, a Core Clients engineer at SoundCloud, discussing how the iOS team scaled its app architecture. Topics include the migration from a monolith to a modularized codebase with 27 modules, use of VIPER architecture, Sourcery for code generation, CocoaPods/Carthage for dependency management, a testing strategy built on over 16,000 unit tests using XCTest, and ongoing challenges around developer tooling awareness and maintenance. The team uses Tuist to generate projects and measure build time regressions, with clean builds currently taking seven to eight minutes and future plans including build artifact caching and dynamic/static linking strategies. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Toss: Building less to ship faster](https://daily.dev/posts/toss-building-less-to-ship-faster-1arhtus0n) · Tuist · 4 upvotes · 0 comments - [Rails World '26: Rails in the Agentic Era](https://daily.dev/posts/rails-world-26-rails-in-the-agentic-era-tnjvjmh6h) · RUBYLAND · 1 upvotes · 0 comments - [The Hidden Cost of Waiting: Build Time as a Productivity Killer](https://daily.dev/posts/the-hidden-cost-of-waiting-build-time-as-a-productivity-killer-kjlvcel46) · Swiggy Bytes · 1 upvotes · 0 comments - [Who Is the Slower App Review Process Actually Stopping? -- Fatbobman's Swift Weekly \#149](https://daily.dev/posts/who-is-the-slower-app-review-process-actually-stopping----fatbobman-s-swift-weekly-149-hxbo09kyz) · Fatbobman · 0 upvotes · 0 comments --- Tags: [#ios](https://daily.dev/tags/ios), [#tuist](https://daily.dev/tags/tuist), [#xcode](https://daily.dev/tags/xcode) [View this post on daily.dev](https://daily.dev/posts/interview-with-donal-o-brien---we-measure-developer-build-times-so-that-we-can-measure-improvements--oil0nvhbd) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Interview with Donal O'Brien - We measure developer build times so that we can measure improvements and regressions","url":"https://daily.dev/posts/interview-with-donal-o-brien---we-measure-developer-build-times-so-that-we-can-measure-improvements--oil0nvhbd","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/interview-with-donal-o-brien---we-measure-developer-build-times-so-that-we-can-measure-improvements--oil0nvhbd"},"datePublished":"2026-08-23T12:20:01.747Z","dateModified":"2026-10-14T02:27:41.873Z","description":"An interview with Donal O'Brien, a Core Clients engineer at SoundCloud, discussing how the iOS team scaled its app architecture. 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