Greg Bolsinga
Software Engineer at Apple
Portland, Oregon, United States
Summary
🤩
Rockstar🎓
Top SchoolGreg Bolsinga is a seasoned software engineer with over two decades of experience building consumer electronics and mobile software, currently working on health at Apple in Portland. He has deep expertise in C, C++, Objective-C and Java across Apple platforms, with production experience from early iPhone Safari and Maps to modern iOS apps. Greg has led large migrations and reliability improvements at scale—most recently optimizing performance and memory for popular open-source iOS libraries like Texture and PINRemoteImage. He combines systems-level thinking (UNIX, OS X) with pragmatic product work—shipping weekly updates to millions of users at Uber and improving the Pinner experience at Pinterest. Known for tackling tricky stability and memory issues, he also has an unexpected history writing CD‑ROM and educational game software and porting Java across historically challenging platforms like z/OS.
11 years of coding experience
27 years of employment as a software developer
BS, Mathematics / Computer Science, BS, Mathematics / Computer Science at University of Illinois Urbana-Champaign
English
Github Skills (15)
uitest10
memory-management10
objective-c10
uikit10
ios10
performance-optimization10
asyncdisplaykit10
xctest10
image-processing10
testing10
image9
unit-testing9
rendering8
render8
ui-design7
Programming languages (9)
Github contributions (5)
TextureGroup/Texture
Mar 2019 - Aug 2020
Smooth asynchronous user interfaces for iOS apps.
Role in this project:
Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:24 reviews, 49 commits, 100 PRs in 1 year 5 months
Contributions summary:Greg primarily contributed to optimizing the performance and stability of the Texture framework for iOS applications. Their work involved identifying and fixing retain cycles within transaction operations, leading to the addition of unit tests to prevent future issues. They also refactored several classes and structs to reduce memory consumption, including shrinking the sizes of critical data structures like `_ASPendingState`, `_ASCollectionPendingState`, `ASDisplayNode`, `ASButtonNode`, and `ASTextNode`. Furthermore, they addressed code consistency by ensuring backing ivars for all properties, and improved tint color behavior within the framework.
asynchronoususer-interfacesrenderingtextureswift
pinterest/PINRemoteImage
Mar 2020 - Jul 2020
A thread safe, performant, feature rich image fetcher
Role in this project:Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:9 reviews, 11 commits, 15 PRs in 3 months
Contributions summary:Greg primarily focused on improving the performance and stability of the image fetching library. They addressed retain cycles in the animated image caching mechanism, fixed memory leaks, and optimized frame index searches. Additionally, the user added a test case to verify the fix and prevent regressions. These changes demonstrate a focus on improving the efficiency and reliability of image handling within the iOS environment.
objective-cimagegifsfeature-richsdwebimage
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