Senior Mobile Engineer (Flutter + iOS)

Description

Summary: Join N-iX as a Senior Mobile Engineer to transition a core mobile platform to Flutter/Dart, architecting and developing robust cross-platform features for a leading digital asset trading platform. Highlights: 1. Pivotal role in transitioning mobile platform to Flutter/Dart 2. Working on impactful projects for industry leaders and Fortune 500 companies 3. Opportunity to mentor junior engineers and contribute to continuous improvement **N\-iX**is a global software development service company that helps businesses across the globe create next\-generation software products. Founded in 2002, we unite 2,400\+ tech\-savvy professionals across 40\+ countries, working on impactful projects for industry leaders and Fortune 500 companies. Our expertise spans cloud, data, AI/ML, embedded software, IoT, and more, driving digital transformation across finance, manufacturing, telecom, healthcare, and other industries. Join N\-iX and become part of a team where your ideas make a real impact. **Our client** is a leading, fully regulated US\-based digital asset trading platform. They provide secure, low\-latency access to cryptocurrency markets, acting as a bridge between traditional finance and the Web3 ecosystem. **The Senior Mobile Engineer** will play a pivotal role in transitioning the core mobile platform from native environments to a unified Flutter/Dart codebase. You will maintain the stability of the existing production iOS app while architecting and developing robust, scalable cross\-platform features, ensuring a seamless migration process. **Key Responsibilities:** * Maintain, enhance, and support our production native iOS application written in Swift. * Collaborate on the design and development of a new Flutter/Dart codebase, ensuring performance and scalability. * Own end\-to\-end delivery of mobile features, including development, testing, release, and ongoing support * Build clean, modular, and reusable code to support scalable mobile architecture * Collaborate with Product, Design, and Backend teams to define requirements and deliver high\-quality features * Optimize app performance, responsiveness, and reliability across a range of iOS devices * Integrate RESTful APIs and ensure efficient data handling and state management * Participate in code reviews and contribute to maintaining high standards of code quality and maintainability * Identify and resolve performance bottlenecks, bugs, and technical issues * Partner with QA and DevOps to support CI/CD pipelines, automated testing, and release processes * Mentor junior engineers and contribute to a culture of continuous improvement **Required Qualifications:** * Bachelor's degree in Computer Science or a related field; * **5\+ years in mobile development experience:** **3\+ years of native iOS (Swift)** and **2\+ years of Flutter/Dart** (or strong cross\-platform experience with proven learning track). * Strong expertise in iOS development: Swift, UIKit/SwiftUI, architecture patterns (MVC, MVVM, VIPER, Clean), and modern concurrency (Combine, async/await) * Hands\-on Flutter experience: Dart, state management (Provider, Riverpod, Bloc, or GetX), and native–Flutter integration (platform channels/pigeon). * Proven experience in app migration or hybrid architectures (native \+ Flutter), ensuring production stability during transition. * Solid experience with REST APIs, async data handling, and state management across mobile layers. * Experience with performance optimization and debugging tools (Xcode Instruments, Flutter DevTools, Firebase). * Strong testing practices: XCTest/XCUITest, flutter\_test/integration\_test, CI\-integrated automation. * Familiarity with mobile security best practices (secure storage, biometrics, certificate pinning, auth flows). * Experience with Git and CI/CD pipelines (Fastlane, Bitrise, GitHub Actions, Codemagic), App Store processes (TestFlight, App Store Connect). * Experience working in **FinTech, banking, trading, or other highly regulated environments**, with a strong collaboration and mentorship mindset across cross\-functional teams (Product, Design, Backend, QA, Android); * **Upper\-Intermediate level of English or higher.** **Preferred Qualifications:** * Exposure to **Android (Kotlin)** and full cross\-platform transitions; **mobile analytics/push notifications** (APNs, FCM); and **crypto / Web3 mobile integrations** \- wallet flows, WalletConnect, MetaMask SDK, transaction signing, on\-chain data display. **We offer\*:** * Flexible working format \- remote, office\-based or flexible * A competitive salary and good compensation package * Personalized career growth * Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) * Active tech communities with regular knowledge sharing * Education reimbursement * Memorable anniversary presents * Corporate events and team buildings * Other location\-specific benefits * not applicable for freelancers