Bartosz Polaczyk

Software Engineer @Apple (Tools&Frameworks)

[Bartosz Polaczyk @norapsi]

@luka_bernardi Aren’t we all umarell engineers now, but giving advices to agents instead?

[Jake Sawyer @Naxum]

Xcode now supports coding agents from Anthropic and OpenAI 😁
https://t.co/2s5wEzrQzb

[Ivan Krstić @radian]

🔺iPhone models announced today include Memory Integrity Enforcement, the culmination of an unprecedented design and engineering effort that we believe represents the most significant upgrade to memory safety in the history of consumer operating systems. https://t.co/ule9gaXzc1

[Spotify Engineering @SpotifyEng]

🤖 What happens when your AI chatbot knows everything your engineering org knows? Way faster answers on everything from corporate policies to internal APIs and more. 🎧 Listen: https://t.co/TGuVSpgetB

[Bartosz Polaczyk @norapsi]

Instruments' CPU Bottlenecks and Processor Traces are truly game changers for code optimization:
https://t.co/WB8iVnln9d #wwdc2025

[Bartosz Polaczyk @norapsi]

If you want to learn how to speed up your UI test authoring in Xcode 26 using recording , watch "Record, replay, and review" session by @MaxHarlynking https://t.co/vFTo8bK2o8

[Bartosz Polaczyk @norapsi]

Join XCTest team! https://t.co/0qX9x9mbfH

[Swift Language @SwiftLang]

Open sourcing Xcode's build engine -- introducing swift-build: https://t.co/huxgprd8v5

[Kacper Harasim @KacperHarasim]

🚀 Help millions of developers build faster apps at Apple!
I’m hiring Performance Tools Engineers to develop Xcode Instruments and create next-generation profiling tools and visualizations targeting all Apple platforms.
📍 Location: Cupertino
🛠️ Tech: Swift, Objective-C, SwiftUI, AppKit
Apply: https://t.co/rOBrFdrCqA

[Bruno Rocha @rockbruno_]

My SwiftConf 2023 talk about App Size @ Spotify is on YouTube now! https://t.co/Dcp8EAE4KU #iosdev #swiftlang

[Bartosz Polaczyk @norapsi]

Open-sourcing XCBuildAnalyzer, a macOS app to visualize Xcode build system graph.
Details are available at Inspecting Xcode’s build system graph at ease: https://t.co/7qDMPxj1Xf

The tool is still in an experimental phase but should be functional already.
https://t.co/qJLKL3iMz6

[Bartosz Polaczyk @norapsi]

@BalestraPatrick Yes, but that error fails the installation. Did not notice the 1:1 scenario as yours - an error in post-installation.

[marciano @marciplan]

Apple is so incredibly bad at explaining these genius little things

[Jon Morgan @heyjonmorgan]

If anybody affected by the layoffs is interested, my team at Square is looking for an engineering manager for the Android Foundation team (core frameworks used to build all of our apps) and a product manager for our core mobile projects. jonm at squareup dot com to connect.

[Bartosz Polaczyk @norapsi]

Context: if you install it manually from UI or a script `xcrun simctl runtime add ...`, a runtime will be placed at /Library/Developer/CoreSimulator/Volumes/

[Bartosz Polaczyk @norapsi]

Even Xcode 14b1 doesn't contain watchOS or tvOS runtime by default, you can manually download dmg and place its content in Xcode's Developer/Platforms/WatchOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/watchOS.simruntime. Useful on CI to not pollute home directory

[Bartosz Polaczyk @norapsi]

I open-sourced a tool to merge several Xcode .dia files into a single file. Could be useful in a Bazel-Xcode integration - multiple per-source-file .dias generated by compilers in a Bazel build can be exposed to Xcode from a single "fake" compilation step: https://t.co/GvbiECCGYs

[Bartosz Polaczyk @norapsi]

@fzwob @twostraws @stroughtonsmith @ChristianSelig XCLogParser can digest Xcode’s .xcactivitylog and includes file build times: https://t.co/YUx1FTwKKR

[Bartosz Polaczyk @norapsi]

I am excited to announce that the project I have been involved is now open source. XCRemoteCache speeds up building iOS apps. Results are impressing, clean builds are down by 70% for the Spotify app.

[Spotify Engineering @SpotifyEng]

A 70% decrease in clean build times 🤯. That’s what XCRemoteCache does for our iOS projects — and it’s what it can do for yours too.

Learn more about it on our blog: https://t.co/AanLxw1gsE

#opensource