Senior Software Engineer (Rails & iOS)

About the role

We’re on a mission to help every athlete run faster, stronger, and more resiliently by building the world’s smartest running shoe. Our team includes ex-Nike execs, ex-Garmin engineers, world-class running coaches, and leading PhDs in biomechanics, biomedical engineering, and AI.

Key Responsibilities

• Work with product and design to turn specs into shipped features.
• Build and maintain our Ruby on Rails backend: REST APIs, Action Cable, and LLM integrations.
• Develop our native iOS app: SwiftUI views, Bluetooth integration, local persistence, and API integration.
• Design new services and evolve our data models to support new product requirements.
• Collaborate closely with firmware and data science teams to deliver seamless full-stack user experiences.
• Integrate third-party libraries and manage dependencies efficiently.
• Debug and troubleshoot production issues across the stack.
• Ensure best practices in architecture and development are followed.

Experience

• 7+ years building and supporting production Rails applications.
• 7+ years building and shipping iOS apps to the App Store (share links to current listings).
• Proven track record shipping full-stack features using Rails and iOS.
• Adept at translating Figma designs into production UI without losing the details.

Skills

• Ruby on Rails.
• Strong understanding of HTTP networking and consuming REST APIs.
• LLM integration, Action Cable/WebSockets.
• AWS, Heroku, or similar cloud platforms.
• SwiftUI, MVVM, SQLite.
• iOS testing frameworks.
• AI-first workflow: fluent across models/tools (e.g. VS Code, Cursor, Claude Code, Zed) for daily development.
• Git and issue tracking systems.

Bonus

• Experience with Core Bluetooth, Python, Android, and other backend technologies.
• Prior experience in sports tech, wearables, or health/fitness devices.
• Passion for running.

Other Details

• Remote-first; must be based in the U.S. or Canada.
• Must be authorized to work in the U.S.