Pinned Tweet
Not one, but six new Agent Skills! Early adopters improved Xcode build times by 78%.
github.com/AvdLee/Xcode-B…
After weeks of work, I launched my latest Agent Skill at Let’s Vision in Shanghai. Here’s how it works:
It runs 3 clean + 3 incremental builds
It analyzes build logs proposes an optimization plan
It applies improvements after you approve
It re-benchmarks and reports the improvement
All free → try it on your Xcode projects.
Let me know how it goes in the replies, and open a PR if you add your results to the README!
github.com/AvdLee/Xcode-B…
After weeks of work, I launched my latest Agent Skill at Let’s Vision in Shanghai. Here’s how it works:
It runs 3 clean + 3 incremental builds
It analyzes build logs proposes an optimization plan
It applies improvements after you approve
It re-benchmarks and reports the improvement
All free → try it on your Xcode projects.
Let me know how it goes in the replies, and open a PR if you add your results to the README!
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I launched a new iOS app!
Yes, it's a crowded scene, but yes, I think we app developers can make a difference with our experience. I'll keep track of achievements in this 🧵
I did not have an app that's usable for a larger audience, so I'm super excited.
Yes, it's a crowded scene, but yes, I think we app developers can make a difference with our experience. I'll keep track of achievements in this 🧵
I did not have an app that's usable for a larger audience, so I'm super excited.
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A little over a week in:
💸 $100 MRR
👥 200+ users
But most of all: real user data that I’ve been able to already use to do great product improvements 🙌
💸 $100 MRR
👥 200+ users
But most of all: real user data that I’ve been able to already use to do great product improvements 🙌
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About 4 weeks later:
👥 405 Installs
💸 5.05% Download-to-Paid, $197 proceeds
🚀 11 updates: iPad, Resizable, and Duo support
💻 Mac version on its way
Some successes:
📈 93% finish onboarding
🎬 Half of installs compress a video within a week
💾 257 GB freed across 1,363 videos
✅ <1% of compressions fail
Some challenges I'm focusing on:
🗜️ Only 1 in 3 installs tries the first compression
👋 ~84% never open the app again after day 0
👬 Invite Friends: 156 saw it, 5 shared a link
🤑 Half of started purchases get cancelled
But don't forget about "The Valley of Disappointment": new apps need time to become successful and this is just the beginning. I'm honestly super happy with these results and it can only get better, as long as I invest in more quality!
👥 405 Installs
💸 5.05% Download-to-Paid, $197 proceeds
🚀 11 updates: iPad, Resizable, and Duo support
💻 Mac version on its way
Some successes:
📈 93% finish onboarding
🎬 Half of installs compress a video within a week
💾 257 GB freed across 1,363 videos
✅ <1% of compressions fail
Some challenges I'm focusing on:
🗜️ Only 1 in 3 installs tries the first compression
👋 ~84% never open the app again after day 0
👬 Invite Friends: 156 saw it, 5 shared a link
🤑 Half of started purchases get cancelled
But don't forget about "The Valley of Disappointment": new apps need time to become successful and this is just the beginning. I'm honestly super happy with these results and it can only get better, as long as I invest in more quality!
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Antoine v.d. SwiftLee retweeted
Not sure if anyone noticed, but I'm slowly rolling out a brand new SwiftLee blog!
It was about time :)
It was about time :)
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Antoine v.d. SwiftLee retweeted
Location-aware code gets messy fast once a real iPhone enters the loop.
I added saved locations to RocketSim so the same GPS scenarios are available across iPhone, iPad, and Simulator. With Xcode 27, you can include system time-zone changes too.
I added saved locations to RocketSim so the same GPS scenarios are available across iPhone, iPad, and Simulator. With Xcode 27, you can include system time-zone changes too.
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Antoine v.d. SwiftLee retweeted
Big milestone reached for RocketTrace!
🎉 1,000 traces analyzed
🪲 8,625 issues found
✨ 779 copied Agent prompts
It's my new app, basically running Xcode Instruments for you using agents.
Have you analyzed your app performance with it already?
🎉 1,000 traces analyzed
🪲 8,625 issues found
✨ 779 copied Agent prompts
It's my new app, basically running Xcode Instruments for you using agents.
Have you analyzed your app performance with it already?
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Xcode 27 MCP and higher token costs, AGENTS dot md best practices, iOS 27 weird Dynamic Island behavior.
It's what's in tomorrow's SwiftLee Weekly:
swiftlee-weekly.com/tomorrow
#swiftdevelopment #iosdevelopment #swiftui #swiftlanguage
It's what's in tomorrow's SwiftLee Weekly:
swiftlee-weekly.com/tomorrow
#swiftdevelopment #iosdevelopment #swiftui #swiftlanguage
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Not sure if anyone noticed, but I'm slowly rolling out a brand new SwiftLee blog!
It was about time :)
It was about time :)
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1
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2,264
Location-aware code gets messy fast once a real iPhone enters the loop.
I added saved locations to RocketSim so the same GPS scenarios are available across iPhone, iPad, and Simulator. With Xcode 27, you can include system time-zone changes too.
I added saved locations to RocketSim so the same GPS scenarios are available across iPhone, iPad, and Simulator. With Xcode 27, you can include system time-zone changes too.
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Xcode's MCP can quietly burn tokens when your agent navigates the Simulator.
avanderlee.com/ai-development…
📸 Why screenshots stay in your context
📊 About 7x more output than RocketSim's CLI
🧭 How to keep your agent on the accessibility tree
#swiftlang #iosdev
avanderlee.com/ai-development…
📸 Why screenshots stay in your context
📊 About 7x more output than RocketSim's CLI
🧭 How to keep your agent on the accessibility tree
#swiftlang #iosdev
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Shoutout to @PaulSolt for testing and reviewing my app:
videocompression.app
I was able to instantly add several improvements after I found out things weren't always working as expected.
Similar shoutouts for @edwardsanchez and @mikaela__caron, all your feedback helped me think out of the box 🚀
videocompression.app
I was able to instantly add several improvements after I found out things weren't always working as expected.
Similar shoutouts for @edwardsanchez and @mikaela__caron, all your feedback helped me think out of the box 🚀
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Big milestone reached for RocketTrace!
🎉 1,000 traces analyzed
🪲 8,625 issues found
✨ 779 copied Agent prompts
It's my new app, basically running Xcode Instruments for you using agents.
Have you analyzed your app performance with it already?
🎉 1,000 traces analyzed
🪲 8,625 issues found
✨ 779 copied Agent prompts
It's my new app, basically running Xcode Instruments for you using agents.
Have you analyzed your app performance with it already?
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Antoine v.d. SwiftLee retweeted
Fast scrolling is where Simulator recordings often make a UI look worse than it is.
I added 120 FPS recording to RocketSim for those cases: HEVC output that more closely follows the on-screen feel.
I added 120 FPS recording to RocketSim for those cases: HEVC output that more closely follows the on-screen feel.
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Antoine v.d. SwiftLee retweeted
I love going deep on improvements, measuring percentage of change along the way. Though, I've not been going as far as @post did for his Swift debouncer, ha!
ivanmagda.dev/posts/swift-de…
ivanmagda.dev/posts/swift-de…
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Antoine v.d. SwiftLee retweeted
Developers who use AI: what are your biggest challenges and questions?
I’ll do my best to answer them!
I’ll do my best to answer them!
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Antoine v.d. SwiftLee retweeted
Apparently, you can now use some View? since Swift 6.4. @sarunw explains how it works.
sarunw.com/posts/optional…
sarunw.com/posts/optional…
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🥇 SwiftUI Performance: Find Redraws in Xcode Instruments
avanderlee.com/swiftui/swiftu…
🥈 How to reduce token usage in Claude Code, Codex, and Cursor
avanderlee.com/ai-development…
🥉 Sendable and @sendable closures explained with code examples
avanderlee.com/swift/sendable…
#swiftlang #swiftlee
avanderlee.com/swiftui/swiftu…
🥈 How to reduce token usage in Claude Code, Codex, and Cursor
avanderlee.com/ai-development…
🥉 Sendable and @sendable closures explained with code examples
avanderlee.com/swift/sendable…
#swiftlang #swiftlee
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Fast scrolling is where Simulator recordings often make a UI look worse than it is.
I added 120 FPS recording to RocketSim for those cases: HEVC output that more closely follows the on-screen feel.
I added 120 FPS recording to RocketSim for those cases: HEVC output that more closely follows the on-screen feel.
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2,505
I love going deep on improvements, measuring percentage of change along the way. Though, I've not been going as far as @post did for his Swift debouncer, ha!
ivanmagda.dev/posts/swift-de…
ivanmagda.dev/posts/swift-de…
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Running out of tokens every single week? day?
Most of it isn't your prompts: it's context your agent re-reads on every turn.
Free prompt that audits your last 7 days of sessions and shows where it goes:
aifundamentals.dev/token-cleanup-…
Reply, and share me your results!
Most of it isn't your prompts: it's context your agent re-reads on every turn.
Free prompt that audits your last 7 days of sessions and shows where it goes:
aifundamentals.dev/token-cleanup-…
Reply, and share me your results!
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Developers who use AI: what are your biggest challenges and questions?
I’ll do my best to answer them!
I’ll do my best to answer them!
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Apparently, you can now use some View? since Swift 6.4. @sarunw explains how it works.
sarunw.com/posts/optional…
sarunw.com/posts/optional…
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4,727