
James Layton
Verified Expert in Engineering
Software Developer
Sterling Heights, MI, United States
Toptal member since April 1, 2025
James is a seasoned iOS engineer with 9+ years of experience building high-quality apps leveraging Swift, SwiftUI, and UIKit. He has a strong background in architecture, back-end integration, and leading projects from ideation to launch. James looks forward to contributing to impactful products with technical and leadership skills.
Portfolio
Experience
- UIKit - 9 years
- Swift - 9 years
- iOS - 9 years
- Agile - 9 years
- Xcode - 9 years
- Firebase - 6 years
- SwiftUI - 4 years
- Objective-C - 3 years
Availability
Preferred Environment
Swift, SwiftUI, Xcode, iOS, Objective-C, Firebase, Supabase, iPad, iPhone, Mobile UI, App Store, UIKit, Core Data, iOS Native Libraries, iOS SDK, Mobile, Mobile Development, API Integration, Model View ViewModel (MVVM)
The most amazing...
...high-traffic iOS app I've led the development of has 600,000+ monthly users and earned extensive praise for performance and smooth design.
Work Experience
Technical Project Lead, iOS and Back-end Systems
Hiro Stories
- Led cross-functional collaboration and project management across teams and partners, aligning hospital stakeholders with technical delivery goals.
- Guided architecture and infrastructure decisions, ensuring scalable solutions that balanced short-term needs with long-term product growth.
- Developed and maintained the iOS app for iPhone and iPad using Swift and SwiftUI, delivering a smooth and child-friendly storytelling experience.
- Built custom REST APIs and back-end logic to enable dynamic content delivery and interactive story playback features.
- Integrated Amazon S3 (AWS S3) for secure, scalable asset storage, improving reliability and performance of content access across devices.
- Set up CI/CD pipelines, optimized GitHub workflows, and led QA efforts to streamline deployments and ensure code quality.
Senior iOS Engineer
accesso
- Built and maintained enterprise-level white-label iOS apps for theme park clients, delivering high-performance, reliable features to over 600,000 monthly users.
- Led the development of a new iOS SDK by extracting reusable core features from existing apps to streamline future B2B integrations.
- Drove architectural design discussions to ensure scalable, modular, and maintainable mobile solutions across teams.
- Created a JavaScript mock API for Apple Wallet Pass integration, improving testing workflow and reliability.
- Mentored junior iOS developers and supported team growth through onboarding, code reviews, and technical guidance.
- Developed an Android POS payment app using Kotlin and Jetpack Compose, ensuring feature parity and alignment with iOS.
- Resolved tough performance issues, optimized app responsiveness, and improved overall architecture for long-term success.
Senior iOS Engineer
Amrock
- Initiated and led the design and implementation of multi-factor authentication (MFA) to strengthen app security and protect user access.
- Improved iOS app architecture by introducing test-driven development (TDD), enhancing code reliability and maintainability.
- Mentored junior iOS developers and hosted internal mobile community sessions to share best practices and uplift team quality.
- Enhanced CI/CD pipelines to streamline app delivery workflows, improving efficiency across the iOS development lifecycle.
- Collaborated closely with solution architects and teammates through pair programming and design discussions to ship robust solutions.
- Supported iOS team growth by participating in interviews and helping onboard talented developers.
- Worked with Android developers to ensure consistent cross-platform features and conducted UI testing for better alignment.
iOS Engineer
Amrock
- Collaborated with solution architects and engineers to deliver scalable iOS solutions through team-driven development efforts.
- Built and enhanced iOS features using Swift and Objective-C, focusing on smooth UX and strong alignment with product goals.
- Applied test-driven development (TDD) to produce reliable, maintainable code and boost long-term development efficiency.
- Contributed to internal mobile community meetings, sharing best practices and encouraging innovation across the iOS team.
- Performed UI testing for Android to ensure cross-platform consistency and supported quality assurance efforts.
- Improved team documentation and SDK guidelines to promote alignment with evolving Apple technologies and standards.
iOS Developer
Sfara
- Led the development of the Sfara Guardian app, collaborating with SDK engineers and integrating APIs to ensure robust architecture and functionalities.
- Migrated key codebases from Objective-C to Swift, reducing technical debt and improving long-term code maintainability.
- Designed reusable and modular components using MVC architecture, laying the groundwork for scalable future development.
- Maintained and tested algorithm-based apps for clients, validating performance and accuracy across multiple use cases.
- Actively participated in Agile stand-ups and grooming sessions, helping to define implementation tasks and overcome blockers.
- Supported senior SDK developers by troubleshooting technical challenges and ensuring software quality across builds.
iOS Specialist
Freelance Clients
- Delivered UI updates and refined visual components across multiple client projects, enhancing user experience and interface consistency.
- Proposed innovative design ideas tailored to client needs, contributing to product direction and feature planning.
- Built functional prototypes to demonstrate concept viability and accelerate decision-making during early-stage development.
- Implemented back-end-connected features for client apps, handling data processing and functional integration.
iOS Developer
Sevenlogics
- Built and enhanced product features and UI components across several iOS apps, contributing to overall functionality and usability.
- Maintained and improved legacy iOS apps, focusing on specific areas to boost stability and performance.
- Collaborated with senior iOS developers and designers to analyze requirements, ensuring efficient and cost-effective solutions.
- Partnered with QA to identify and fix bugs, improving app quality and user experience.
- Solved technical challenges alongside senior developers, accelerating development and enhancing code quality.
- Mastered the internal SDK to boost productivity and streamline new feature implementation.
- Delivered content updates and app improvements on schedule, supporting key business and project goals.
Experience
Web3C
https://apps.apple.com/us/app/web3c/id6466555489Sfara Guardian
https://apps.apple.com/us/app/sfara-quest/id1559949848By completing simple, guided tasks, users contribute to training and refining Sfara’s detection algorithms, helping improve emergency response accuracy and reliability. All data collected is anonymized via a user ID and stored securely in the cloud, with no personally identifying information beyond location. Sfara Guardian empowers users to actively participate in a mission to build safer communities, one task at a time.
Amrock Apps
https://apps.apple.com/us/developer/amrock-llc/id715582070The My Appraisal app helps appraisers manage property inspections, submit reports, and track orders on the go, improving turnaround times and communication. The My Signing app enables signing agents to view, schedule, and complete closing appointments efficiently while staying updated in real time. Additionally, Amrock Connect was an internal collaboration app built to streamline communication and coordination among teams, helping staff stay informed and connected, though the project was later paused.
Education
Bachelor's Degree in Computer Science
University of Pittsburgh - Pittsburgh, PA, USA
Skills
Libraries/APIs
iOS Native Libraries, CocoaPods
Tools
Xcode, Git, Jira
Languages
Swift, Objective-C, TypeScript, Kotlin, C++
Frameworks
SwiftUI, UIKit, Core Data, iOS SDK, StoreKit, Core ML
Paradigms
Agile, Agile Project Management, REST, Mobile Development, Model View ViewModel (MVVM), Scrum, Object-oriented Programming (OOP), Test-driven Development (TDD)
Platforms
iOS, Firebase, Mobile, Azure, Android
Storage
Amazon S3 (AWS S3)
Other
iPhone, Software Development Lifecycle (SDLC), Mobile Apps, SDKs, Mobile UI, App Store, Front-end, User Interface (UI), Consumer-facing Products, Early-stage Startups, API Integration, Async/Await, iPad, Apple Wallet, Mentorship, Interviewing, CI/CD Pipelines, APIs, Online Payments, OAuth, Architecture, Software Architecture, Minimum Viable Product (MVP), AVFoundation, Supabase, Algorithms, Encryption, Jetpack Compose, OpenAI, Cryptocurrency, Computer Science, Startups, ChatGPT API, Machine Learning
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