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# Software Engineer II

- **Company:** NINJATRADER, LLC
- **Location:** Chicago, IL, United States (Remote available)
- **Experience:** Expert
- **Salary:** $140,000.0 - $190,000.0
- **Contract:** Permanent contract
- **Skills:** Flutter, Java (Programming Language), Multitier Architecture, Adobe InDesign, IOS Applications, Application Frameworks, Continuous Integration, Software Debugging, Dependency Injection, Software Design Patterns, Model View ViewModel, Object-Oriented Software Development, Performance Tuning, Software Engineering, Strategies of Testing, WebSocket, Data Processing, Kotlin, Dart, Reactive Programming, Restful APIs
- **Published:** October 9, 2026
- **Apply:** https://startup.jobs/sr-mobile-engineer-ii-ninjatrader-9505888

## About the Role

* 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

Bonus Points for:

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

## Description

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 oncmobile 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