Drew Sen
Verified Expert in Engineering
iOS Developer
Vancouver, BC, Canada
Toptal member since June 23, 2023
Drew is a seasoned iOS developer with 10+ years of experience crafting exceptional mobile experiences. Deeply familiar with Apple's ecosystem, he excels at creating high-performance, polished iOS apps. Drew's passion for innovation and staying at tech's forefront make him a sought-after expert. His ability to transform ideas into seamless user experiences ensures an unparalleled experience. Whether building apps or enhancing iOS ecosystems, Drew brings his clients' vision to life.
Portfolio
Experience
- Git - 11 years
- iOS - 11 years
- Xcode - 10 years
- Design Patterns - 10 years
- UIKit - 10 years
- Agile - 10 years
- Swift - 7 years
- Model View ViewModel (MVVM) - 6 years
Availability
Preferred Environment
Swift, Xcode, UIKit, Git, Model View ViewModel (MVVM), iOS, Agile, Design Patterns, SwiftUI, iOS Frameworks, Lottie, Firebase
The most amazing...
...app I've contributed to is the iOS version of Bria, which reached the top 100 in its category on the App Store and was featured in "Apps We Love."
Work Experience
Senior iOS Developer
Bally
- Implemented smart onboarding, next-generation widgets, and enhanced user experience for the latest versions of iOS, using mainly SwiftUI and Combine for this purpose.
- Used SwiftUI to create layouts with vertical, horizontal, and overlay stack views with VStack, HStack, and ZStack, respectively, and used async/await, actors, and tasks for asynchronous methods.
- Led the hiring and mentoring of a team of 10-12 mobile developers, overseeing technical projects, one-on-one meetings, and code reviews.
- Collaborated with product managers and designers to develop the latest features, serving as project stakeholders' main technical point of contact.
Senior iOS Developer
PayByPhone
- Rearchitected the app's transactional data model, Core Data layer, and REST interface, increasing app performance and reducing crashes by 98%.
- Implemented a test-driven development methodology and established a continuous integration system using Nimble, Quick, Git, Fastlane, and Bitrise.
- Designed a system for uploading and downloading transaction receipt images while the application runs in the background using PromiseKIT and GCD.
- Updated legacy Objective-C code to Swift and used bridging headers to connect Objective-C and Swift libraries.
iOS SDK Developer
CounterPath
- Acted as a counterparty in the evaluation of technical solutions delivered by external providers working remotely and provided technical debt assessment on the existing iOS codebase.
- Reviewed and provided sign-off on architecture proposals for the VoIP company Dialpad and Rogers, focusing on VoIP and security aspects of the SDK and corresponding iOS apps.
- Used the following major protocols and architectures: SIP, XMPP, NAT, TURN, STUN, RTP, TLS, HTTP, and HTTPS, implemented in sample iOS apps.
Experience
Sports Betting App for iOS
https://apps.apple.com/ca/app/bally-bet-sportsbook-casino/id1633504950I ensured an intuitive and visually appealing user interface that enhanced the overall user experience. I integrated various external tools and APIs to provide real-time updates, live scores, and dynamic odds for a wide range of sports events.
I implemented robust data storage and retrieval mechanisms to securely manage user preferences, transaction history, and account information. This gave users a seamless and personalized betting experience across multiple devices.
Additionally, I established a reliable network layer that facilitated smooth communication between the app and the back-end servers. This involved implementing RESTful APIs and handling network requests efficiently, ensuring fast and accurate data retrieval.
Overall, my contributions to the Bally Bet sports betting app have helped create a polished and feature-rich platform that enables users to enjoy the excitement of sports betting while ensuring a smooth and seamless user experience.
Education
Master's Degree in Computer Science
The University of British Columbia - Vancouver, BC, Canada
Skills
Libraries/APIs
Google Maps SDK, CocoaPods, Lottie-iOS
Tools
Xcode, Git
Languages
Swift, Objective-C
Frameworks
UIKit, iOS Frameworks, Core Data, Core ML, Metal, SwiftUI, ReactiveSwift
Platforms
iOS, Firebase, Android, MacOS
Paradigms
Model View ViewModel (MVVM), Agile, Design Patterns, Object-oriented Programming (OOP)
Other
iPad, Lottie, Custom Keyboards, Networks, Software Engineering, Artificial Intelligence (AI), Computer Graphics, SDKs, VoIP, SIP, XMPP
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