Hybrid Senior Engineer, Mobile Apps

at Hex Trust

• Job title: Senior Engineer, Mobile Apps
• Job type: Full Time
• Experience level: Senior
• Salary: Not specified
• Degree requirement: No Education Requirement
• Tech skills: Android, Dart, Flutter, iOS, Kotlin, Swift
• Location requirements: Hybrid, Ho Chi Minh City, Vietnam

About the role

• Senior Mobile App Engineer at Hex Trust migrating native Swift and Kotlin apps to Flutter. Collaborating with product managers and leveraging AI-assisted development tools for optimization.

Responsibilities

• Analyze the existing Swift (iOS) and Kotlin (Android) native apps and define a structured migration strategy to a single shared codebase (Flutter preferred).
• Deliver a high-quality, feature-complete cross-platform application that maintains the look, feel, and performance of the native originals.
• Identify and surface risks, propose trade-offs, and keep stakeholders informed throughout the migration.
• Use AI coding assistants (e.g. GitHub Copilot, Claude) to accelerate code generation, refactoring, and test authoring.
• Leverage Figma-to-code workflows via MCP integrations to automatically scaffold UI components directly from designer handoffs.
• Write and maintain comprehensive unit and widget tests, using AI tools to maximise coverage with minimal overhead.
• Stay on the leading edge of AI tooling and proactively propose new techniques that improve team velocity.
• Work directly with the product manager, business stakeholders, and designers — translating business needs into technical solutions without requiring exhaustive requirement documents.
• Proactively surface problems and ambiguities before they become blockers, and always come with proposed solutions and trade-offs.
• Participate in design reviews and provide early technical feedback to prevent costly late-stage rework.
• Own app architecture decisions — state management, navigation, data layer, and integration patterns.
• Enforce security best practices, particularly around authentication, data encryption, secure storage, and privacy compliance relevant to financial applications.
• Set and uphold code quality standards via code review, linting, and automated testing pipelines.
• Choose and evolve your own toolchain — we open to your suggestions and proposals

Requirements

• 5+ years of professional mobile development experience.
• Hands-on expertise with Flutter and Dart; strong understanding of widget lifecycle, state management (Riverpod, Bloc, or similar), and platform channels.
• Solid experience with at least one native platform (Swift/iOS or Kotlin/Android) — you need a good understanding of the existing codebases you'll be migrating.
• Demonstrated use of AI coding tools in a professional context (code generation, test writing, or design-to-code pipelines).
• Proven ability to work autonomously, manage your own priorities, and communicate proactively with non-technical stakeholders.
• Strong problem-solving mindset — you identify issues early, think creatively, and propose concrete solutions.
• Proven track record of submitting and shipping apps to both the App Store and Google Play, including full ownership of the submission and approval process.

Benefits

• Competitive Salaries & Bonuses
• Generous Amounts of Paid Time Off (incl. leave for Birthdays, Work Anniversary, and Mental Health etc.)
• Medical & Retirement Plans
• Professional Learning and Development Opportunities
• Elevate your work using cutting-edge technology
• Fun & friendly office spaces in Hong Kong, Singapore, Dubai and Vietnam
• Regular company & social events