Xcode

Xcode disk space can grow rapidly without you noticing. Especially these days, with multiple agents turning multiple worktrees into silent disk space occupiers. Where I used to only focus on deleting old Simulators every now and then, I'm now also actively managing worktrees and derived data folders. There are great ...

Testing iOS Time Zones is a typical validation path that's difficult without actually traveling yourself. You can apply all kinds of protocols and mock versions of your app, but having iOS act like it's actually traveling between time zones is a real challenge. Ideally, you'd test apps like travel apps ...

Apple launched Xcode 27 during WWDC'26, introducing a bunch of agentic development improvements, including official agent skills. As you've learned from my 9-Step Framework for Choosing the Right Agent Skill, it's important to pick skills from authoritative sources. Apple absolutely counts like one, of course! Official Agent Skills will impact ...

Xcode Instruments is a powerful tool that ships with Xcode and lets you analyze, debug, and optimize your code, including Swift Concurrency. It comes with so-called templates that consist of multiple instruments. After running your app through Xcode Instruments, you'll get a detailed overview of the performance of your app ...

App Preview Videos are important for both App Store presence and app marketing. Yet it can be challenging to create realistic videos, especially if your app runs only on a physical device. You also often have a more realistic version of your app running on your iPhone, as you're using ...

AI Agents change how we develop, and you might think you no longer need Xcode Instruments for performance iterations. When I started developing apps in 2009, we would constantly use Xcode Instruments' Time Profiler and other instruments to analyze and improve our apps' performance. Devices were simply much slower, so ...

It's very likely that your app is running multiple network requests during each app session. Many apps don't even work without a network connection, making it crucial to optimize the performance and caching for the best user experience. While network requests execute in the background, their responses are often printed ...

RocketSim 15.0.0 introduces a unique VoiceOver Navigator and a post editor for screenshots and videos. Combined with the option to record videos in 120 frames per second (FPS), it now offers the best recording capabilities in the market of Xcode Simulator developer tooling. These are just the major changes that ...

Xcode build optimization ensures both your clean and incremental builds remain performant. New Xcode versions or WWDC announcements introduce new best practices that you need to apply to ensure having the best build performance. While you might expect Xcode to apply new build settings automatically, the truth is you often ...

Test your app's VoiceOver support using Xcode's Simulator and create high-quality 120 FPS recordings. That's what RocketSim's major 15.0 release will bring, and it's not all! We also created insights based on your networking sessions and we're moving towards AI supportive insights. If you're new to RocketSim, check it out ...

Whether it's a new or an existing Xcode project, I always apply these changes immediately when I open it for the first time. I've been developing apps since 2009, and some of these changes prevent tech debt from day one. Even though we should trust Xcode's defaults, the reality is ...