Sr. Mobile Engineer II (Flutter)

NinjaTrader; Chicago (IL); On-site; USD 130,000 - 210,000; Full time

Job summary

NinjaTrader in Chicago seeks a Sr. Software Engineer II specializing in Flutter to lead mobile architecture, mentor engineers, and deliver scalable cross‑platform apps. You will shape technical direction, drive quality, and ensure reliability across iOS and Android.

You will own feature lifecycles, participate in design reviews, and collaborate with Product and Design to elevate user experience. Strong Flutter, Dart, and mobile‑dev experience are required.

Qualifications

• 6+ years of professional software engineering experience.
• 2+ years of hands-on Flutter and Dart in production.
• Understanding mobile architecture, state management, and design patterns.
• Experience with Flutter testing strategies: unit, widget, integration, end-to-end.
• CI/CD automation for mobile delivery.
• RESTful APIs, WebSockets, and offline data handling.
• Strong communication and teamwork in an Agile environment.
• Solid OOP design fundamentals.

Responsibilities

• Own lifecycle of features: debugging, documenting, testing, releasing, and monitoring.
• Attend daily stand-ups and team meetings to align tasks.
• Contribute to the technical roadmap for mobile architecture and tooling.
• Participate in design reviews, architecture discussions, and performance improvements.
• Implement robust Flutter solutions with proper state management and DI.
• Collaborate with Product and Design to improve mobile UX.
• Investigate issues, mitigate them, and propose preventative measures.
• Improve observability, monitoring, and crash analytics for stability.
• Foster a culture of technical excellence and collaboration.

Skills

Flutter

Dart

Mobile architecture

State management

CI/CD for mobile

RESTful APIs

OOP

Agile

Communication

Job description

JOIN US ON OUR MISSION TO BECOME THE #1 RETAIL TRADING PLATFORM IN THE WORLD

Welcome to the dynamic world of NinjaTrader! As an industry-leading trading platform and futures broker, we’re empowering traders to take control of their financial destiny. How do we do it? We provide cutting‑edge products and services that enhance the trading journey. Whether a seasoned pro or just starting out, NinjaTrader equips traders with award‑winning software and brokerage services to navigate the world’s leading financial markets with confidence.

Our growth story is nothing short of exhilarating. Since 2003, NinjaTrader has been dedicated to understanding and supporting traders on their journey toward trading triumph. Through those efforts, our user base has grown to over 2 million users and we have become the number one rated futures brokerage worldwide.

But we’re not stopping there. We’re constantly evolving, pushing boundaries, and modernizing the futures industry. Our commitment to innovation means users will always have access to dynamic tools, real‑time support, and a community of like‑minded traders.

So, why work at NinjaTrader? Here, you’re not just part of a team; you’re part of a movement. We empower employees to reach new heights in their careers by providing a dynamic culture focused on social connection, professional development, and employee recognition initiatives. Sounds too good to be true? ++Take it from our employees.++

Join us as we redefine what’s possible in trading, advocate for our customers, and continue our journey toward becoming the world’s top retail‑focused trading platform in the world.

The team

NinjaTrader is a futures‑focused brokerage offering low commissions, award‑winning trading platforms, and a suite of customizable tools for active traders. The platform delivers integrated multi‑device trading across desktop, web, and mobile, with access to thousands of third‑party trading apps and add‑ons.

The opportunity

Join our Mobile Engineering team as a Sr. Software Engineer II specializing in Flutter. You will champion the execution of our mobile architecture, mentor engineers, and deliver scalable, high‑performance applications that provide a seamless cross‑platform experience. You will also shape technical direction across teams, set a high standard for engineering excellence, and drive quality and reliability across our mobile products.

In this role you will:

• Own the life cycle of features through debugging, documenting, testing, releasing, and monitoring
• Attend daily stand‑ups and regular team‑wide meetings to discuss current and upcoming tasks
• Contribute to the technical roadmap for mobile architecture, frameworks, and tooling
• Participate in design reviews, architecture discussions, and performance optimization efforts across iOS and Android
• Implement robust, maintainable Flutter solutions that follow best practices for state management, dependency injection, and reactive programming
• Collaborate with Product and Design teams to iteratively improve the user experience on mobile platforms
• Investigate issues, mitigate them, and recommend preventative measures
• Improve observability, monitoring, and crash analytics to ensure product stability and quality
• Foster a culture of technical excellence, innovation, and collaboration

What you bring

• 6+ years of professional software engineering experience
• 2+ years of hands‑on Flutter and Dart experience in production environments
• Understanding of mobile architecture, state management, and design patterns (e.g. BLoC, MVVM, Clean Architecture)
• Experience maintaining testing strategies for Flutter applications, spanning unit, widget, integration, and end‑to‑end levels
• Familiarity with building CI/CD automation for mobile delivery
• Understanding of RESTful APIs, WebSockets, and offline data handling
• Familiarity optimizing performance, reliability, and user experience across diverse devices
• Ability to perform in a team environment adopting agile principles
• Strong written and verbal communication skills
• Strong grasp of OOP design principles

Nice to haves

• Knowledge of native iOS (Swift) and Android (Kotlin/Java) integration
• Experience with fintech or trading platforms
• Contributions to open‑source frameworks or SDKs

We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender, gender identity or expression, or veteran status. We are proud to be an equal opportunity workplace.