Senior Software Engineer, Rips (Mobile)

triumph-arcade; San Francisco (CA); On-site; USD 120,000 - 180,000; Full time

Job summary

Triumph is seeking a talented mobile engineer to own core features in React Native and Expo, from design discussions to launch and iteration. You’ll shape motion, transitions, and perceived performance to create a native-like user experience while ensuring correctness and polish in a high-stakes trading-card app.

You’ll dive deep into native modules when needed, partner with backend teams on API design, and own reliability metrics such as startup time and crash-free sessions.

Qualifications

• Experience with React Native and Expo in shipping apps.
• Strong mobile engineering background with end-to-end ownership.
• Ability to debug performance and rendering issues on mobile devices.

Responsibilities

• Build and own core product features in React Native and Expo, from design through launch.
• Focus on motion, transitions, perceived performance, and small details that delight users.
• Delve into native modules and platform APIs when necessary to solve problems.
• Collaborate with backend engineers on API and data model design, pushing back on contracts that hurt the client.
• Own performance and reliability: startup time, frame rate under load, crash-free sessions.
• Set architectural patterns and guardrails to help future features ship quickly.

Skills

React Native

Expo

Mobile engineering

Ownership

Performance optimization

Debugging

Tools

Native iOS

Android

Native modules

API design

Job description

The Role

Rips is our collectibles trading card app, it lives on mobile, and it is growing fast. You'll be building it.

This is the product, not a port of it. Our app is React Native and Expo. You'll be shipping to real users who are trading real value, which means correctness, latency, and polish are not separable concerns here. A dropped state update is not a cosmetic bug when there is money on the other side of it.

You will own significant surface area from day one: features end to end, the interaction quality that makes them feel native, and the technical decisions underneath. We're a small team, so the person who designs something is the person who ships it and the person who owns it afterward.

What You'll Do

• Build and own core product features in React Native and Expo, from design discussion through launch and iteration.
• Take the user experience seriously: motion, gesture, transitions, perceived performance, and the small details that separate an app people tolerate from one they open every day.
• Go below the abstraction when the problem requires it. Native modules, platform APIs, rendering behavior, build configuration.
• Partner with backend engineers on API and data model design, pushing back when a contract makes the client worse.
• Own performance and reliability for what you ship: startup time, frame rate under load, crash free sessions.
• Raise the floor for the team. The patterns you set should make the next feature faster and make the right approach obvious to whoever builds it.

What We're Looking For

• Strong mobile engineering background. React Native and Expo experience is ideal. Native iOS or Android engineers who want to move into React Native will also do well here.
• Real ownership of consequential work. Tell us about the feature you designed and shipped and still maintain, not the test coverage number you moved.
• Deep platform understanding. You know what is happening on the device, not just which component to reach for. You can debug something the framework does not explain.
• Craft. You have opinions about how an interaction should feel and you can implement them.
• A track record of creating leverage. You establish the architecture and the guardrails that let mid level and junior engineers move quickly without breaking things, you articulate a technical direction, and you defend it well enough that people follow it.
• Fluency with AI as a tool, never as a replacement for understanding. You use it aggressively and can explain every line that ships under your name.

In person. Our team gathers 5 days a week at Triumph's headquarters at Levi's Plaza in San Francisco.