Roy Marmelstein
Staff Engineer - IOS at Spotify
Stockholm, Stockholm County, Sweden
Summary
🤩
Rockstar🎓
Top SchoolRoy Marmelstein is a Staff iOS Engineer based in Stockholm with a decade of experience building polished, performance-conscious mobile apps and frameworks. Currently at Spotify, he blends deep Swift expertise with a history of shipping reusable libraries—authoring popular open-source projects for interpolation-driven animations, phone number parsing, zipping utilities, and localization—that reflect a strong focus on developer-friendly APIs. He’s comfortable across low-level integration (minizip support, password-protected archives) and high-level UX features (peek/pop, gesture-driven animations), and has contributed to large-scale frameworks like AsyncDisplayKit and Spotify’s HubFramework. A former Senior iOS Engineer at Zenly and long-time freelance developer, Roy balances product-focused iteration with careful testing and sample apps to make adoption straightforward. Fun fact: his GitHub work shows a habit of improving ergonomics—adding sample apps, file browsers, and easy APIs—to turn technical libraries into practical tools for other engineers.
10 years of coding experience
6 years of employment as a software developer
Brighton CollegeBSc Hons, Accounting and Finance, BSc Hons, Accounting and Finance at University of Warwick
English, French, Hebrew
Github Skills (34)
unit-testing10
uitextview10
objective-c10
file-management10
ios10
mobile-development10
internationalization10
interpolation10
ui-design10
zip10
asyncdisplaykit10
data-structure10
mobile-application10
regular-expression10
uid10
Programming languages (8)
Github contributions (5)
marmelroy/Interpolate
Mar 2016 - Jan 2021
Swift interpolation for gesture-driven animations
Role in this project:
Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:11 releases, 99 commits, 11 PRs in 4 years 10 months
Contributions summary:Roy appears to be primarily responsible for developing the core functionality of the iOS application. The user started with an initial setup of the test suite. They focused on implementing a Swift interpolation framework. The user then improved the API and added a sample application with view controller elements to test the interpolation functionality. Finally, the user worked on improvements to the API to support UI elements like colors.
animationinterpolationswiftgesture-driven-animationsgesture
marmelroy/PeekPop
Feb 2016 - Dec 2016
Peek and Pop with backwards-compatibility
Role in this project:Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:8 releases, 79 commits, 11 PRs in 9 months
Contributions summary:Roy primarily contributed to building an iOS application with peek and pop functionality. Their work included the initial setup and implementation of delegate methods, the creation of a custom gesture recognizer, and the development of a custom UI window and view to handle the peek and pop animation. The user focused on providing a custom implementation that also integrates with the native 3D Touch API when available.
peekpopbackwards-compatibilitycompatibility
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