Nathan is available for hire
Hire NathanNathan Wei-Li Chan
Verified Expert in Engineering
iOS Developer
Portland, OR, United States
Toptal member since January 9, 2020
Bio
Nathan has over a decade of experience in varying engineering roles. He started at Microsoft and continued as a full-stack developer for several years before transitioning to iOS. He has recently been a freelance iOS and visionOS developer focused on developing augmented reality (AR) apps for various startups. Previously, Nathan led an iOS team in building AR apps that integrated with physical toys for kids, promoted problem-solving, and developed digital literacy via 2D games and AR activities.
Portfolio
Toptal
ARKit, Swift, iOS, iOS SceneKit, VisionOS, Augmented Reality (AR), Eye Tracking...
Gumroad (Freelance)
Swift, SwiftUI, UIKit, iOS, WidgetKit, Firebase, In-app Purchase (IAP)...
Seedling
ARKit, Swift, iOS, SpriteKit, Core ML, Augmented Reality (AR), Objective-C...
Experience
- iOS - 12 years
- Swift - 8 years
- Augmented Reality (AR) - 7 years
- ARKit - 7 years
- iOS SceneKit - 7 years
- SwiftUI - 5 years
- Core ML - 5 years
- VisionOS - 1 year
Work Experience
Freelance iOS & visionOS Engineer
2020 - PRESENT
Toptal
- Worked with multiple clients spanning various industries, primarily focused on augmented reality projects involving prototyping, research, development, and App Store launches.
- Built a first-of-its-kind application for Vision Pro, one of the first apps to launch on the visionOS App Store.
- Focused on developing apps in Swift and building custom features and functionality using ARKit, SceneKit, SpriteKit, and other core Apple libraries.
- Provided high-level technical guidance and product direction for early-stage and experimental projects, particularly in the augmented reality space.
Technologies: ARKit, Swift, iOS, iOS SceneKit, VisionOS, Augmented Reality (AR), Eye Tracking, SwiftUI, Facial Tracking, App Development, Large Language Models (LLMs), Mobile App Development, Artificial Intelligence (AI)
Senior iOS Engineer
2020 - 2024
Gumroad (Freelance)
- Functioned as the sole iOS developer, responsible for all of Gumroad’s iOS initiatives, including new feature development and product launches of multiple apps, back-end integration, and bug fixes.
- Wore many hats, collaborating with designers, product leaders, engineers, marketing, and customer support to ensure a high-quality user experience and stable App Store releases.
- Entered the era of AI and evolved into a heavily AI-assisted product engineer, increasing my productivity and expertise in the field by many multiples—primarily with the help of Cursor, Claude, ChatGPT, and many other AI-powered tools.
Technologies: Swift, SwiftUI, UIKit, iOS, WidgetKit, Firebase, In-app Purchase (IAP), App Development, Mobile App Development
Lead iOS Engineer
2017 - 2020
Seedling
- Owned multiple iOS apps developed for kids that merged physical toys and digital experiences using augmented reality. The flagship product was an AR teddy bear sold in many retail stores.
- Worked initially as the sole iOS developer, built out a small team of mobile developers, and fostered a positive engineering culture to deliver quality user experiences across a suite of apps.
- Acquired by BEGiN, whose mission was to provide children with the best educational start possible, the seedling team was brought in to enhance their subscription offering with a physical product paired with a digital AR experience.
- Launched an iOS app for BEGiN that utilized AR and machine learning to encourage kids to learn through play while interacting with the real world.
Technologies: ARKit, Swift, iOS, SpriteKit, Core ML, Augmented Reality (AR), Objective-C, App Development, Mobile App Development
Senior Software Engineer
2013 - 2016
SurveyMonkey
- Owned the core functions of SurveyMonkey Audience, a marketplace business bringing together market researchers looking for insights and survey-takers incentivized by donating to charity.
- Led multiple cross-organization initiatives, including API implementation and UX integration projects to launch survey-taking functionality in the SurveyMonkey iOS and Android apps.
- Made key contributions to an entire site redesign, with a focus on responsive design for mobile and tablet, A/B rollout plans and key metrics reporting.
- Led a rewrite of the entire customer-facing checkout flow using React and Redux.
Technologies: Python, iOS, React, JavaScript
Software Development Engineer in Test
2009 - 2012
Microsoft
- Played a core role in the feature design and testability of the data migration process of SharePoint Online customers to the data-center infrastructure.
- Authored automation for the migration process which saved hundreds of developer hours for the core engineering team.
- Drove and ensured the high availability of the entire SharePoint Online service to meet a 99.9% uptime SLA, while working closely with an operations team.
- Authored several monitoring-and-debugging tools to increase efficiency and reduce on-call engineer investigation time by several magnitudes.
- Helped shepherd the team’s growth from seven engineers to over 200.
Technologies: SQL, Windows PowerShell, C#
Project History
iScape Landscaping App for Apple Vision Pro
A first-of-its-kind augmented reality application for Apple Vision Pro, one of the first apps built for the visionOS platform. It enabled users to design and visualize their landscape project in AR before spending real time and money.
It was built using all modern Apple libraries, including SwiftUI and new spatial concepts introduced in visionOS.
It was built using all modern Apple libraries, including SwiftUI and new spatial concepts introduced in visionOS.
Gumroad iOS App
https://apps.apple.com/us/app/gumroad/id916819108A feature-rich eCommerce app built with modern Apple libraries in Swift and SwiftUI. I was the sole iOS developer responsible for new feature development, back-end integration, and bug fixes. The project contained complex user flows, including in-app purchasing, authentication options, audio and video players, and advanced UI to visualize sales data.
AR Shoe Fitting iOS App
Developed an app for an innovative shoe company that used AR to scan users' feet to find the perfect-fitting shoe.
The initiative of this project was to improve the user foot-scanning experience, which captured photos of each foot and fed them into a back-end computer-vision model for 3D reconstruction for shoe fitting. We successfully launched a working prototype using various ARKit features, including plane detection, vision libraries for shape detection, and SceneKit to create a spray-painting experience. The prototype accurately captured and uploaded photos with corresponding camera and geometric data to reconstruct a 3D model of each foot, bundled in a user-friendly app experience.
The initiative of this project was to improve the user foot-scanning experience, which captured photos of each foot and fed them into a back-end computer-vision model for 3D reconstruction for shoe fitting. We successfully launched a working prototype using various ARKit features, including plane detection, vision libraries for shape detection, and SceneKit to create a spray-painting experience. The prototype accurately captured and uploaded photos with corresponding camera and geometric data to reconstruct a 3D model of each foot, bundled in a user-friendly app experience.
Parker: Your Augmented Reality Bear iOS App
https://www.macworld.com/article/230674/parker-your-augmented-reality-bear.htmlThis project involved an augmented reality app that encourages kids to role-play as doctors, promote problem-solving, and develop digital literacy skills through 2D games and AR activities.
I was the lead iOS engineer on the project, managing a small team of engineers to develop and launch numerous innovative features.
The app was built entirely in Swift, using the latest Apple SDKs, including ARKit and Core ML.
I was the lead iOS engineer on the project, managing a small team of engineers to develop and launch numerous innovative features.
The app was built entirely in Swift, using the latest Apple SDKs, including ARKit and Core ML.
Education
2004 - 2009
Bachelor's Degree in Computer Science
University of Toronto - Toronto, Canada
Skills
Libraries/APIs
Firebase iOS SDK, SpriteKit, React
Tools
Git, Xcode, Jira, Slack
Languages
Swift, Python, Objective-C, C#, JavaScript, SQL, HTML, CSS
Frameworks
ARKit, iOS SceneKit, Core ML, SwiftUI, Windows PowerShell, UIKit, WidgetKit
Paradigms
App Development
Platforms
iOS, VisionOS, Firebase, MacOS, WatchOS
Other
Augmented Reality (AR), Mobile App Development, Facial Tracking, Artificial Intelligence (AI), Eye Tracking, IAP SDK, 3D Modeling, In-app Purchase (IAP), Large Language Models (LLMs)
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