Justin Steffen
Senior Engineering Manager at Uber
San Francisco, California, United States
Summary
🤩
Rockstar🎓
Top SchoolJustin Steffen is a senior engineering leader with 20+ years of experience scaling mobile platforms and leading high-impact teams in both high-growth and regulated environments. He has driven organization-wide initiatives at Square—supporting 400+ mobile engineers—that improved reliability, developer productivity, and user-facing performance (notably launching an automated crash triage system and unifying multiple apps into a single binary). Previously he built and launched Xero’s greenfield Expenses app used by 500K+ monthly users and introduced BFF and CI/CD practices to accelerate delivery. A hands-on leader who still contributes to mobile open-source work (UI components and composable state machines in Swift/Kotlin), he blends deep technical craft with empathetic people management and a focus on measurable outcomes. Based in San Francisco, he teaches and mentors engineers from diverse backgrounds and is now seeking Manager/Director/Head of Engineering roles to help teams scale technology and impact.
12 years of coding experience
18 years of employment as a software developer
B.S. Management Information Systems, B.S. Management Information Systems at University of South FloridaThe CodePath
English
Github Skills (8)
swift10
workflow-engine10
ios10
ui-design10
state-machine10
reactive9
kotlin3
android3
Programming languages (8)
Github contributions (5)
square/workflow
Nov 2019 - Apr 2022
A Swift and Kotlin library for making composable state machines, and UIs driven by those state machines.
Role in this project:
Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:3 reviews, 43 commits, 28 PRs in 2 years 4 months
Contributions summary:Justin's commits primarily focus on developing the UI for the "Workflow" library, specifically implementing components for a split-screen container. The contributions include creating view controllers, handling layout, and integrating the UI with the workflow engine. They also include snapshot testing and enhancements such as animating ratio changes and adding a separator, demonstrating a focus on improving the user experience and visual presentation of the library.
kotlin-librarystate-machinesmachinesandroidkotlin
JustinDSN/FEWD_14_SF_Students
Jan 2014 - Mar 2014
Contributions:22 commits in 1 month
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