Troy Stephens

Senior Software Engineer

Mountain Lakes, New Jersey, USA
about.me • LinkedIn • GitHub • X
troy@coherencelabs.com

Producing well-built, clearly understood systems in the course of relentless, real-world problem-solving has been my focus as a software engineer. I’ve programmed hardware to the metal, developed GNC code for SpaceX’s SuperHeavy booster, contributed 16 years of enhancements to Apple’s AppKit framework, implemented 3D game rendering and art pipelines, built advanced device drivers and a revolutionary HTML+WordPress editor for macOS, and helped app teams troubleshoot complex problems and build new features. I’ve been a conference speaker and mentor to other developers, have enjoyed working with amazing people, and welcome new challenges and opportunities.

API Design & Implementation

Our single most important task on the AppKit team was designing clear, capable, extensible, and durable APIs that boost app developers’ productivity. In my 16 years contributing to AppKit, I authored and circulated Objective-C and Swift API proposals designed in close adherence to key principles of clarity, consistency, and low-impedance interoperability that guided our endeavors — marshaling the results through discussion and iterative refinement to consensus. These proposals contributed additions and enhancements to the public AppKit and SwiftUI APIs used by app developers, and adapted our Objective-C AppKit APIs to fit seamlessly into Swift’s syntax and conventions. I implemented proposed AppKit improvements while maintaining strong compatibility guarantees for existing apps, and managed gentle phase-out of deprecated APIs. My team and I helped review and improve proposals in other frameworks including UIKit and SwiftUI. Our process and guidelines influenced later efforts such as Swift’s API Design Guidelines, bringing the same careful consistency to all Apple platforms.

Human Interface Development (UI / UX)

In my time at Apple, I was fortunate to work closely with members of Apple’s renowned Human Interface (HI) team to prototype and refine changes through many major iterations of macOS’ look and feel. I contributed to design review discussions, offering feedback and helping bridge designs to engineering possibilities to realize designers’ intent for numerous new and updated UI features. I then worked across framework layers to implement each new look in my UI components. All of this flowed naturally from my earlier work in game development, where I worked closely with artists to realize desired UX results on Sony PlayStation hardware.

Mission-Critical Flight Software

As a SpaceX engineer, I contributed to flight control software that flew on the Starship project’s SuperHeavy booster on April 20, 2023. Working with an incredibly talented team, I assisted with sensor interfacing and Guidance, Navigation, and Control (GNC), working in C++ and a Python-based scripting language.

OS Development

I helped Apple ship 16 years of macOS releases. I contributed API design, new features, enhancements, and fixes to AppKit and macOS, frequently collaborating across system framework layers to achieve results. I helped internal and 3rd party app teams troubleshoot problems and reach solutions. I maintained binary compatibility for client apps, digging in for deep debugging sessions when needed to solve issues in complex third party apps, including Microsoft and Adobe titles. I also generated several new OS feature ideas that I prototyped and presented.

App Development

I designed and developed TypeMetal — Coherence Labs’ groundbreaking semantic HTML editor and WordPress client for macOS. Working solo, I produced an editor that one reviewer described as “objectively superior to Dreamweaver’s Design view in every imaginable way.”

TypeMetal’s unique engine combines a directly editable CSS-styled view with an efficient keyboard interface and precise control over generating sparse, streamlined, modern HTML that greatly exceeds expectations for a visual web content editor. TypeMetal’s editing engine relies heavily on careful, undoable DOM tree manipulation.

In the course of creating and deploying TypeMetal to Apple’s Mac App Store, I’ve built experience with App Store requirements, the submission/review process, and how to get things done from the outside. I’ve also leveraged my Apple platform expertise to help 3rd party apps like Tower add new features and enhancements.

TypeMetal 3’s development has entailed a move to Swift and TypeScript for most new code, and has expanded the scope of my work to encompass UIKit-based native iOS development.

Game & Game Tools Development

In the game industry, I’ve built art pipeline tools to process 3D assets and manage VRAM layout, and implemented special effects, retexturing, LOD and dynamic subdivision, and realtime animation adjustments, dropping from C++ to R3000 assembly where needed to optimize for tightly resource-constrained Sony PlayStation hardware. My math and physics background has provided a solid foundation for conceptualizing and solving problems in 3D worlds.

Graphics & Animation

I’ve worked with everything from high-level 3D and 2D APIs such as SceneKit, Open Inventor, OpenGL, CoreAnimation, CoreImage, and CoreGraphics, to vendor APIs such as DirectX, 3Dfx Glide, and Sony PlayStation, to chipset- and framebuffer-level programming on early PCs and Apple // hardware. At Apple, I integrated CoreAnimation-based layer-backing and CoreImage-based image processing capabilities into AppKit, and worked with CoreGraphics engineers to realize new window effects and optimize view redraw. In the game world, I built art pipeline tools to process 3D assets and manage VRAM layout, and implemented special effects, retexturing, LOD and dynamic subdivision, and realtime animation adjustments with carefully stabilized numerics. My past independent work includes a subset OpenGL implementation in C++ and x86 ASM, and a raytracer with Windows frontend written in C++.

Networking and Backend Interfacing

I developed TypeMetal’s content sync engine and REST- and XML-RPC based WordPress interfacing, and did chipset-level serial comms. programming and protocol implementation back when dialup ran the world.

Presenting

As an engineer on the AppKit team, I enjoyed the opportunity to present work at Apple’s World Wide Developer Conference (WWDC), leveraging Apple-internal speaker training and content refinement support to give 12 talks over the years, to rooms of up to 3,000 attendees. This most often involved designing a presentation from scratch and developing illustrative sample code, sometimes in collaboration with co-presenters. I also designed and gave internal “SpotlightOn” talks for fellow Apple engineers. I enjoy delivering quality content, motivating ideas clearly, and helping seed the spark that leads to new ideas, products, and enhancements.

Example: Advances in UI Data Sources (2019)

Technical Writing

I’ve developed carefully documented sample code, written detailed API proposals, and wrote TypeMetal’s User Guide.

Math & Physics

My math and physics background has been indispensable in supporting my work and thinking — from 3D game mechanics and graphics, to helping develop GNC code for the world’s biggest rocket.

Video and Audio Production

I’ve done writing and basic video and audio content production for CoherenceLabs’ YouTube channel and The No Fear Pioneer podcast, acquiring new skills and learning what I need to know as I go.

Next Frontiers

In hand with my passion for next physical frontiers, I’m strongly interested in new virtual frontiers in decentralized finance and blockchain commerce, and their potential to support self-sovereignty and censorship-resistant communication. I’m actively absorbing knowledge about related systems and technologies, including Bitcoin, Ethereum, Avalanche, Rust, and Go, and would welcome the opportunity to work more deeply in these areas. I’ve also begun leveraging TypeScript to refactor TypeMetal’s DOM tree editing engine for broader portability.