Staff iOS Engineer (Contract)

High Roller Technologies; United States; On-site; USD 180,000 - 240,000; Full time

Job summary

Rolr is seeking a Staff-level iOS Engineer on contract to deliver the iOS experience for our prediction markets platform. You’ll work across React Native and Swift with the CPO and partner engineers to ship regulated finance-category consumer apps through App Store approval.

Remote work is available for candidates in the US or EU. This senior, hands-on role requires immediate start and full-time engagement with potential future extensions.

Qualifications

• 8+ years of professional iOS engineering with shipped consumer apps.
• Experience taking multiple apps through App Store review, preferably finance/trading.
• Strong Swift experience (SwiftUI & UIKit) and production React Native.
• Performance-focused, with profiling, animation timing and memory management.
• Experience with mobile design systems and component libraries.

Responsibilities

• Design and build the iOS interaction layer across React Native and Swift.
• Own App Store submission strategy, guideline compliance, TestFlight, and rollout.
• Build real-time trading interfaces that perform under live market conditions.
• Develop native Swift modules where React Native falls short, including charts.
• Contribute to the native design-system components and platform integrations.
• Implement authentication flows (OAuth2/OpenID, passkeys, biometrics).
• Improve app performance including cold start, frame time, and memory usage.
• Support localization, gating, and multi-market functionality.
• Review internal and partner-engineer work to high standards.

Skills

iOS engineering

Swift

SwiftUI

UIKit

React Native

App Store submission

Performance optimization

Regulated apps

Fintech/trading

Tools

Keycloak

OIDC

Passkeys

Job description

About Rolr

ROLR is building a prediction markets platform delivering the frontier of trading on sports, culture, economics, AI, commodities, and geopolitics.

Role Overview

We're looking for a Staff-level iOS Engineer on a contract basis to help deliver the iOS experience for our prediction markets platform through App Store submission and launch. This is a senior, hands-on engagement for someone who has shipped regulated or finance-category consumer apps through App Store review multiple times. You'll work across React Native and Swift with the CPO, our product engineering team, and our platform partner's engineers.

This role can be based remotely in the US or EU.

Key Responsibilities

• Design and build the iOS interaction layer across React Native and Swift
• Own App Store submission strategy, guideline compliance, TestFlight, and phased rollout for a regulated finance-category app
• Build real-time trading interfaces that remain performant under live market conditions
• Develop native Swift modules where React Native is not sufficient, including charts, performance-critical views, and platform integrations
• Contribute to the native side of our design-system component library
• Implement authentication flows including OAuth 2.0 / OpenID Connect, passkeys, and Touch ID / Face ID via LocalAuthentication
• Improve app performance, including cold start, frame time, and memory usage
• Support jurisdiction-aware gating, localization, and multi-market functionality
• Review customer-facing work from internal and partner engineers to a high standard

You’ll need to:

• Have 8+ years of professional iOS engineering experience with shipped consumer apps
• Have taken multiple apps through App Store review, including finance, trading, or another sensitive category
• Have strong Swift experience, including SwiftUI and UIKit, and production React Native experience
• Have strong performance instincts, including profiling, animation timing, list virtualization, and memory management
• Have experience with mobile design systems and component libraries
• Be available to start immediately and commit full-time for the engagement

Preferred Experience

• Trading, fintech, or real-time consumer applications
• Keycloak or comparable OIDC identity platforms, passkeys, and biometric authentication
• Live Activities, widgets, App Intents, or rich notifications
Real-time charting or data visualization
• AI-assisted development workflows

Contract Details

• Initial 3-month contract engagement, with a full-time commitment and defined deliverables. There may be potential to extend the engagement or convert to a full-time role.