Kern Jackson

Kern Jackson

Apple Platforms Engineer
Seattle, WA · Kerntronics LLC · hello@kerntronics.com

I'm an Apple platforms engineer with 15+ years building native apps for iOS, iPadOS, macOS, watchOS, tvOS, and visionOS. I solve real customer problems with thoughtful UI and UX that is fast and accessible.

I work in Swift, SwiftUI, UIKit, and AppKit, from Objective-C through Swift 6 data-race safety, and I'm a longtime teacher, speaker, and organizer in the Apple developer community.

Connect with me on social media!

Experience

June 2025 - Present

Platforms Engineer (Contract)

Apple
  • Delivered critical apps, features, and bug fixes in Swift with SwiftUI, UIKit, and AppKit, focusing on information architecture, layout, and mapping features to real user workflows
  • Cut the main view's render time by 60% by profiling with Instruments (Time Profiler, Animation Hitches, and SwiftUI) and eliminating unnecessary SwiftUI view updates
  • Migrated Swift packages to structured concurrency (async/await, async let, task groups, actors) and enabled Swift 6 data-race safety checking across them
  • Eliminated flaky tests and crashes caused by data races by moving @MainActor isolation up to the type level and writing a SwiftLint rule to enforce the pattern
  • Shipped fixes and features on a near-weekly release cadence, delivering larger features within weeks and complete apps in a few months
  • Used engineering reviews to simplify and modernize the team's approach, including size classes, planning docs, detailed PRs, and actionable review feedback
  • Applied LLMs and multi-agent workflows to prototypes, profiling, code reviews, and process improvements
January 2025 - June 2025

Senior Mobile Developer (Contract)

Amazon Kuiper
  • Implemented feature flows in Swift and SwiftUI, working with designers
  • Collaborated across teams to define and maintain a shared component library
  • Ported shared business logic to iOS with Kotlin Multiplatform, and built additional flows in Kotlin and Compose Multiplatform
June 2021 - June 2025

Senior iOS Developer

Kerntronics LLC
  • Delivered features in Swift, UIKit, and SwiftUI for clients including The BLVD, Envoy, and GeoSafe
  • Under deadline, restored VoiceOver on Envoy's building-access kiosk sign-in screen by restructuring configuration-driven UIKit views, unblocking a government customer's contract renewal
  • Worked on localization for Envoy's iPad app, particularly localization testing
  • Reduced memory use and eliminated crashes in a photo grid by serving smaller thumbnails from the database and caching them for a UICollectionView
  • Prototyped an Apple TV app for a client
  • Resolved infrastructure issues and significantly sped up test suites to increase team velocity
January 2014 - June 2021

Analyst / Software Developer

American Fidelity
  • Took the app from 2.2 to 4.8 stars across 70,000+ reviews as its user base grew by several orders of magnitude
  • Member of a four-person team that delivered the iOS and Android apps, later writing major new functionality in Swift (1 through 5), SwiftUI, Kotlin, and Jetpack Compose
  • Designed and built an offline-first iOS and iPadOS claims flow that cached form definitions, saved progress locally, and uploaded queued submissions automatically when back online, so users could file claims anywhere
  • Collaborated with UX on comps, user studies, and rapid prototypes, and proved out designs in user testing
  • Invented a document scanner and a smart keyboard entry accessory, and built provider lookup with maps and receipt OCR with Vision
  • Introduced code reviews, Gitflow, SwiftLint, Swift packages, and automated tests, and owned CI/CD for iOS and Android with fastlane, Azure DevOps, and TestFlight
  • Resolved a duplicate mailing issue that saved millions, and built a solution that saved two support FTEs annually
  • Coached junior developers and interns

Apps

Some of the apps I've written or contributed to over the years.

  • Lights Out Game (LOG) for iOS, iPadOS, macOS, and visionOS, ready for Apple Vision Pro launch day
  • Sounds Neapolitan, a visionOS exclusive
  • Corner Clock, a watchOS exclusive
  • AF Mobile for iOS and watchOS
  • Envoy for iPadOS
  • Apple TV: a personal Pokédex app and a client prototype

Education

University of Central Oklahoma

Bachelor of Computer Science
  • Designed and built the iOS client for a research grant project
  • Shipped a UIKit and OpenGL game to the App Store, rewritten from Unity to cut launch time from 9 seconds to near-instant

Skills

Programming Languages & Tools
Technical Knowledge
  • Expert in Swift, SwiftUI, UIKit, Objective-C, Xcode, the Human Interface Guidelines, Instruments, LLDB, Swift packages, git, XCTest, and user testing
  • Modern Swift: structured concurrency (async/await, async let, task groups, cancellation), actors, Sendable, @MainActor isolation, Swift 6 language mode and data-race safety
  • UI and accessibility: AppKit, Core Animation, size classes and adaptive layout, VoiceOver, Dynamic Type, localization
  • Testing and delivery: Swift Testing, UI tests, The Composable Architecture, SwiftLint, CI/CD with fastlane, TestFlight, Azure DevOps, and GitHub Actions
  • Data and networking: SwiftData, Core Data, REST, GraphQL, offline-first design
  • Experience with Kotlin, Kotlin Multiplatform, Compose Multiplatform, Jetpack Compose, Java, .NET, RoR, Python, SQL, Elixir, Phoenix, Blender, and Material Design
  • AI workflows: multi-agent and LLM tooling for prototyping, profiling, and code review

Transferable Skills & Personality Traits
  • Experience working across teams and with customers
  • Effective written and verbal communication
  • Presentation skills
  • Curious and willing to learn
  • Ethical and honest
  • Willing to share credit on accomplishments with teammates

About

I'm an Apple platforms engineer with 15+ years building native apps for iOS, iPadOS, macOS, watchOS, tvOS, and visionOS. I solve real customer problems with thoughtful UI and UX that is fast and accessible, grounded in deep knowledge of the Human Interface Guidelines. I have years of experience identifying pain points, inventing solutions, and collaborating with designers, engineers, subject matter experts, and product owners.

As a marathoner and triathlete, I bring the discipline and consistency learned in endurance sports to my work. I am motivated by exploring new territory, whether it's learning a new framework, pattern, language, or tackling new challenges in software development.

Media

YouTube Content

Building a SwiftUI app Step-by-Step

In this project, I progressively built a small SwiftUI app that displays the NASA photo of the day. Each video broke down the app into the smallest piece of work that I could imagine at the time. There are 45 videos in this series.

Code and a screenshot of the NASA photo of the day app
Kern giving a talk
Past Presentations

CocoaHeads OKC Presentations

This is a playlist of talks I gave at CocoaHeads OKC in partnership with Techlahoma. The topics cover SwiftUI, Apple Watch development, and augmented reality with ARKit.

Community Involvement

  • Active Seattle Xcoders member
  • spokaneOS founder and organizer
  • Longtime CocoaHeads OKC co-organizer
  • Gave talks on ARKit, watchOS, and SwiftUI, some of which can be found on Techlahoma's YouTube
  • Created an educational YouTube series building a SwiftUI app from scratch and without third-party libraries
  • Joined WWDC week to attend and volunteer at community events (2024, 2025)
  • Regular attendee at 360 iDev, Deep Dish Swift, and Community Kit
  • Filed Feedback Assistant reports on SwiftUI

Need App Development Services?

Do you need help with your app or want to build something together?

Shoot me an email and let's get the conversation started!

hello@kerntronics.com

Or connect with me on social media!