Senior Mobile Engineer

What you'll do

• Design, develop, and maintain scalable mobile applications using Flutter and Dart, with a strong emphasis on code quality and maintainability
• Integrate with backend payment APIs and native platform capabilities, handling edge cases such as ambiguous or delayed responses
• Write robust unit, widget, and integration tests for all new features and ensure proper validation for critical payment and KYC flows
• Collaborate cross-functionally with backend, frontend, product, and design teams to define, design, and ship high-impact features
• Guide and mentor junior and mid-level engineers, providing technical leadership through code reviews, design discussions, and pairing sessions; review native plugin code in Kotlin and Swift as part of the role
• Lead by example in enforcing clean architecture, clear documentation, and reliable observability practices
• Identify and resolve performance bottlenecks, improve app reliability, and optimise for correctness and user experience
• Stay up to date with emerging mobile technologies and propose improvements aligned with business goals
• Build software with security and compliance in mind, ensuring proper access control, secure handling of regulated identity data, and adherence to the Vietnam Law on Identification
• Manage Play Store and App Store release pipelines and support operational readiness of mobile services

What you should have

• Bachelor's degree in Computer Science, Software Engineering, or related field.
• Has shipped a consumer-facing fintech or wallet app at scale through full release cycles.
• Has handled store-policy escalations and review responses on Play Store or App Store.
• Deep Flutter and Dart — state management, async and isolate patterns, platform channels, performance profiling, custom rendering when needed.
• Reads and patches native plugin code in Kotlin and Swift, and Objective-C where needed. This is the bar for senior Flutter on this team, not a separate role.
• Mobile build, signing, and store-policy fluency for both Play Store and App Store, including policy-review handling.
• Payment SDK integration — card capture, in-app 3DS, biometric prompts, secure input handling.
• Mobile security — secure storage (Keychain, Android Keystore), certificate pinning, anti-tamper basics, jailbreak and root detection.
• Native build systems — Gradle, Xcode build configurations, signing config.
• Strong technical communication in English; documents mobile-specific decisions for cross-functional partners.
• Has owned the end-to-end app lifecycle — store releases, beta channels, and policy responses.
• Comfortable participating in mobile-impacting incident response.