iOS × Threading
iOS Threading
We track 14 iOS Threading case studies from 7 engineering teams. SwiftLee, Thumbtack and Expedia write about it most. Many posts also cover Performance Profiling and Architecture. The posts run from 2020 to 2026. The newest is from August 2026.
iOS Threading articles 1–14 of 14
Sendable and @Sendable closures explained with code examples
Antoine van der Lee tackles the #1 migration blocker in Swift 6: Sendable conformance. If you're seeing data race warnings pile up, this deep dive shows exactly how to fix them.
Swift 6.4: What's New in Concurrency
Antoine van der Lee breaks down Swift 6.4's concurrency updates so you don't have to parse through Evolution proposals yourself. These aren't just theoretical improvements: they solve real friction points in as...
Unexpected Task suspension points in Swift Concurrency
Antoine van der Lee uncovered a sneaky Swift Concurrency bug that was silently destroying his app's performance. The culprit? An innocent-looking Task that was secretly hopping on and off the main thread hundre...
Immediate tasks in Swift Concurrency explained
Antoine van der Lee tackles a subtle but powerful new Swift 6.2 feature that most developers will misuse. Task.immediate promises faster execution, but it can easily freeze your UI if you're not careful.
Thumbtack's Journey to Swift 6
Scott Southerland from Thumbtack just shared what most iOS teams won't tell you: migrating to Swift 6 took 16+ months and broke their entire test suite. Here's the battle-tested playbook they wish they'd had.
Swift Thread Safety: NSLockThreadSafeAccess vs DispatchQueueSafeAccess
Kcrdissanayake from PickMe Engineering breaks down a critical choice every Swift developer faces: how to safely manage shared state across threads without killing performance.
Swift Actor in Unit Tests
Abdul Moiz from Thumbtack reveals how Swift 6's concurrency checks broke their entire test suite. Their solution? A clever protocol-based pattern that makes actors mockable without sacrificing thread safety.
Ready for Swift 6
Dave Verwer and Sven A. Schmidt from Swift Package Index reveal that 43% of Swift packages are already data race safe. The Swift 6 migration is happening faster than expected.
How We Optimized Concurrency Using Node.js at Skeelo
Skeelo's engineering team achieved a 30% performance boost by rethinking one simple thing: when NOT to use await in Node.js.
Building a Modern iOS Networking Library with Swift Concurrency
Emre Havan from Getir rebuilt their entire iOS networking stack from scratch. The result? A modern, async-first library that eliminated memory leaks and cut boilerplate code—but not without hitting some painful...
Async/Await in Swift: Modern Concurrency Patterns
Asukhija from Expedia Group shows how two simple keywords can eliminate callback hell in Swift. If you've ever drowned in nested closures, this is your lifeline.
Swift Async Algorithms
Tony Parker from Apple just dropped a game-changer for async Swift development. If you've been wrestling with time-based operations or multi-input streams, this new package solves problems you didn't know had e...
Introducing Swift RunOnce
Daniel Roth from Thumbtack's iOS team just solved a problem every Swift developer has faced: ensuring code runs exactly once without the brittle boolean flags that break at scale.
Swift Atomics Library
Karoy Lorentey from Apple just dropped Swift Atomics, bringing C/C++ style low-level atomic operations directly into Swift. This changes the game for systems programmers who've been blocked from building concur...