Recent Posts
Why Swift Migration Tooling Matters
Swift offers migration tooling to help you migrate existing code to new upcoming features. Swift Evolution proposals on GitHub will ...
The 5 biggest mistakes iOS Developers make with async/await
App Store Rejections, your UI freezing for 5 seconds, and migration projects taking months instead of days (even if you’ve ...
Derived Data: 5 Things iOS Developers Do Wrong
The Derived Data folder is one of the most important directories an iOS developer relies on. While you don't work ...
The best mobile app monitoring product just keeps getting betterSentry automatically captures crashes recorded on macOS, iOS, and tvOS to make sure you're shipping the best experience to your users. Oh... and also Emerge Tools is now a part of Sentry, so things are getting even better. Use coupon code SWIFTLEE2025 for Sentry’s Business Plan and get started now with 2 free months.
The Essential Swift Concurrency Course for a Seamless Swift 6 Migration.
Learn all about Swift Concurrency in my flagship course offering 13 modules, 78 lessons, videos, code examples, and an official certificate of completion.
Updated for Swift 6.2 and now available with a limited-time launch offer.
Swift Keywords
Do you know how to use each keyword in Swift?
Click on the keyword to learn more and explore code examples.
Career Advice – Grow your career
Looking to grow your career in iOS development? With years of experience leading teams at WeTransfer and building SwiftLee into a go-to resource for over 140,000 developers monthly, I offer insights on everything from launching successful side projects to scaling app users. Whether you’re refining your Swift skills, building an online presence, or creating passive income with courses, I’m here to help you navigate your journey.
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The Going Indie Podcast
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Learn more about Swift
Swift Computed Property: Code Examples
Computed properties are part of a family of property types in Swift. Stored properties are the most common, saving and ...
Property Wrappers in Swift explained with code examples
Property Wrappers in Swift enable you to extract common logic into a separate wrapper object. Introduced at WWDC 2019 and ...
Async await in Swift explained with code examples
Async await is part of the new structured concurrency changes that arrived in Swift 5.5 during WWDC 2021. Concurrency in ...
FREE 5-Day Email Course: The Swift Concurrency Playbook
A FREE 5-day email course revealing the 5 biggest mistakes iOS developers make with with async/await that lead to App Store rejections And migration projects taking months instead of days (even if you've been writing Swift for years)
Learn SwiftUI
SwiftUI Toggle: A Complete Guide
A SwiftUI Toggle is a common UI element that allows users to switch between states. It often turns a binding ...
@ViewBuilder usage explained with code examples
The @ViewBuilder attribute is one of the few result builders available for you to use in SwiftUI. You typically use ...
Universal Links implementation on iOS
Universal Links allow you to link to content inside your app when a user opens a particular URL. Webpages will ...
Build Apps Faster using RocketSim
Recommend by Apple as an “Essential Tool for Developers”, RocketSim helps thousands of engineers to save hours per week. Discover these articles and learn how you can leverage RocketSim to improve your workflow:
App Actions
- Inspect network traffic using the Xcode Simulator
- Universal Links implementation on iOS
- Deeplink URL handling in SwiftUI
- Location Simulation in Xcode’s Simulator
- Optimizing your app for Network Reachability
- Testing push notifications on the iOS simulator
App Actions Perform Menu
- Localization testing in Xcode
- User Defaults reading and writing in Swift
- Xcode Simulator Directories Exploration
RocketSim Tools
Combine all the things
Combine and Swift Concurrency: A threading risk
Many developers are migrating from Combine to Swift Concurrency. Swift Concurrency is here to stay, and Combine hasn't received updates ...
@Published risks and usage explained with code examples
@Published is one of the property wrappers in SwiftUI that allows us to trigger a view redraw whenever changes occur ...
RunLoop.main vs DispatchQueue.main: The differences explained
RunLoop.main and DispatchQueue.main are often used as schedulers within Combine. During code reviews, I often encounter inconsistency in using one ...
The best mobile app monitoring product just keeps getting betterSentry automatically captures crashes recorded on macOS, iOS, and tvOS to make sure you're shipping the best experience to your users. Oh... and also Emerge Tools is now a part of Sentry, so things are getting even better. Use coupon code SWIFTLEE2025 for Sentry’s Business Plan and get started now with 2 free months.
Dive into Core Data
How to observe NSManagedObject changes in Core Data using Combine
Observing changes in Core Data NSManagedObject instances with Combine publishers can be a great solution to keep your user interface ...
Data validation on insertion, update, and deletion in Core Data
Data validation in apps is important to make sure we save data conforming to the business rules. A name should ...
Derived Attributes to improve Core Data Fetch Performance
Derived attributes are available since iOS 13 and aim to improve fetch performance in many different scenarios. Although we have ...
Be an expert on Xcode
Derived Data: 5 Things iOS Developers Do Wrong
The Derived Data folder is one of the most important directories an iOS developer relies on. While you don't work ...
Sparkle: Distribution apps in- and out of the Mac App Store
By implementing Sparkle into RocketSim, I've been able to allow developers to install my app on macOS outside of the ...
RocketSim 13.0: Builds Apps Faster
RocketSim is a developer tool that gives your Xcode Simulator extra functionalities to increase day-to-day development productivity. A floating window ...
Get better at debugging
Introducing Diagnostics: Improved Debugging and User Support
A diagnostics report that helps you solve bugs and improve user support at the same time. I've been writing apps ...
Network Link Conditioner: Simulating Slow Networking
The Network Link Conditioner allows you to test your apps under slow networking conditions on macOS and iOS. The tool ...
Memory consumption when loading UIImage from disk
Memory consumption can quickly increase if you load many images from the disk using UIImage. You'll generally load images from ...
Improve your workflow
Testing push notifications on the iOS simulator
Testing push notifications in the iOS simulator makes adding support for remote notifications much more effortless. However, you often must ...
Designing Apps: 5 Methods to improve your workflow
Designing apps can be challenging if you don't have a design background. Many of you who read my blog are ...
Test-Driven Development (TDD) for bug fixes in Swift
Test-driven development (TDD) is a technique that requires you first to write a failing test before you start implementing a ...
Optimize yourself and improve
App Store Optimization: Real-world Best Practices
App Store Optimization is important for every app's success. You've spent a lot of time building a fantastic product, so ...
Introducing Diagnostics: Improved Debugging and User Support
A diagnostics report that helps you solve bugs and improve user support at the same time. I've been writing apps ...
Billing Grace Period Explained: How It Works and Why It Matters
Users with auto-renewable subscriptions can enter a billing grace period if their automatic payment failed. In this period, they can ...
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Most Popular Posts
- Why Swift Migration Tooling Matters
- Async await in Swift explained with code examples
- The 5 biggest mistakes iOS Developers make with async/await
- MainActor usage in Swift explained to dispatch to the main thread
- Sendable and @Sendable closures explained with code examples