Senior Mobile Engineer, Flutter
What we’re looking for
We are seeking a talented, endlessly curious individual to join our team. You’ll be working closely with our group of companies in the fintech sector as part of the Engineering department. This company is a leading B2B fintech platform in its field, processing over US$2B across multiple currencies annually. We’re looking for individuals who are driven to create meaningful value, take full ownership of what they build, and thrive in a fast-paced, high-growth environment. If you’re motivated by impactful work and eager to be part of an innovative team, we’d love to hear from you.
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.
About Us
Xenith
is a B2B payment service provider focused on enabling seamless cross-border commerce. With an MSB license in Canada and PJP III license in Indonesia, we offer global merchants a one-stop solution to manage multi-currency payments - with a strong focus on alternative payment methods in emerging markets. Our deep regional expertise and strong partnerships with top local gateways, we simplify the complexity of fragmented payment landscapes, helping global merchants expand faster and more efficiently. At Xenith, we believe in building a culture where people feel empowered, trusted, and challenged to do their best work. Join us as we build the financial infrastructure of tomorrow!
Department
Engineering
Role
Mobile Engineer
Locations
Vietnam
Remote status
Hybrid