Principal Mobile Engineer

Payoneer is investing in the next generation of its mobile application: lightweight, high-performance, and designed as a platform that lets product teams contribute features independently while the app remains coherent, fast, and stable as a whole. The host application will provide the common foundations — observability, logging, navigation, identity, networking, feature flags, release tooling, automation — and product teams will plug into it through a clear contribution model.

We are hiring two Principal Mobile Engineers to define and build this foundation alongside the existing mobile team. Together you will own the tech stack decision — native iOS and Android, Flutter, React Native or a hybrid — and you will shape the platform every product team at Payoneer ships mobile features on top of. The two-Principal structure gives us the capacity to build the platform properly, and the optionality to specialize one Principal per native platform if we go that route.

What you’ll own

You will own the tech stack decision and the rationale behind it. You will run the evaluation — native (Swift / Kotlin) vs Flutter vs React Native vs hybrid — against real constraints: performance, binary size, hiring market, team contribution model, build and release velocity, long-term maintenance cost. You will make the call jointly with your peer Principal and you will be expected to defend it under scrutiny from engineering, product, and executive leadership.

You will build the host application foundation. The architecture, the module boundaries, the navigation and lifecycle model, the dependency injection approach, the state management patterns, the threading and concurrency model, the network stack, the persistence layer, the observability and logging backbone, the release and rollout machinery, the testing strategy at every level of the pyramid. Every product team’s first impression of mobile at Payoneer will be the abstractions you ship.

You will define the contribution model that product teams use to deliver features into the host app. Module boundaries, public API surface, lifecycle hooks, dependency policy, build and integration patterns, version compatibility, and the developer experience that makes contributing a feature fast and contributing a bad one hard. You will own the standards every contributing team writes against.

You will own performance, binary size, startup time, frame rate, memory, and battery as first-class engineering disciplines with measured budgets and gates. You will own crash-free rate and stability as platform commitments. You will own the CI/CD, signing, release, and rollout pipeline for the app, and the observability that makes a production issue debuggable in minutes rather than days.

You will partner with the Application Foundations Crew and the Cloud Platform Base, DevEx, and Network and Security teams to make sure mobile integrates cleanly with the platform — APIs, events, identity, secrets, automation and the shift-left controls that apply on the mobile side as much as the server side. You will partner with product engineering across the company to bring contributing teams into the platform and keep them productive in it.

What we’re looking for

You have ten or more years of mobile engineering experience and you have built mobile applications from the ground up — not joined them, not iterated on them, but defined the foundation and shipped it to production at scale. You have an honest, scarred view of what mobile platform decisions cost three years after you make them.

You are deeply expert in at least one of iOS or Android, and seriously fluent in the other. On iOS that means Swift, the Swift concurrency model, UIKit and SwiftUI, the Apple toolchain and release process, and the parts of the ecosystem most engineers learn the hard way. On Android that means Kotlin, coroutines and Flow, the Android lifecycle, Jetpack and Compose, Gradle in earnest, RxJava where it still lives, and the same hard-won understanding of the ecosystem.

You understand the cross-platform landscape with the same honesty. You have an opinion on Flutter, KMP, and React Native that goes beyond preference — performance characteristics, ceiling, where each shines, where each fails — and you can defend the recommendation you would make for a fintech app at Payoneer’s scale.

You have built and operated a modular mobile platform before, or something close enough that you understand the trade-offs: how to define module boundaries that survive ten product teams contributing in parallel, how to keep the host app coherent when contributors disagree, how to version a contribution model without breaking everyone, and how to keep the binary lean as the surface grows.

You think in budgets and measurements. You have driven startup time, frame rate, binary size, and crash-free rate as numbers on a dashboard. You understand mobile observability at a level beyond crash reporting, and you have shipped the instrumentation needed to debug productio.

You communicate clearly with engineers, product partners, and executives. You can write a one-page architecture proposal, run an RFC that actually converges, demo what you built so other engineers want to use it, and explain a stack decision to a CPO in language they care about. You handle disagreement well — including with your peer Principal — and you know how to land a joint decision.

Nice to have

Experience integrating AI capabilities into mobile applications — on-device models, conversational and agent UI patterns, latency-sensitive AI features, and the privacy and offline considerations that come with them — is a strong plus, given Payoneer’s AI-native platform direction.

Why this role matters

The mobile app is the surface Payoneer customers touch after Web. The foundation you build will compound for years. You will have unusual scope to define what good looks like for Payoneer, and credibly for the industry, at the point where regulated payments, mobile engineering at scale, and AI-native development converge.

The Payoneer Ways of Working

Act as our customer’s partner on the inside Learning what they need and creating what will help them go further.

Do it. Own it. Being fearlessly accountable in everything we do.

Continuously improve Always striving for a higher standard than our last.

Build each other up Helping each other grow, as professionals and people.

If this sounds like a business, a community, and a mission you want to be part of, apply today.

We are committed to providing a diverse and inclusive workplace. Payoneer is an equal opportunity employer, and all qualified applicants will receive consideration for employment no matter your race, color, ancestry, religion, sex, sexual orientation, gender identity, national origin, age, disability status, protected veteran status, or any other characteristic protected by law. If you require reasonable accommodation at any stage of the hiring process, please speak to the recruiter managing the role for any adjustments. Decisions about requests for reasonable accommodation are made on a case-by-case basis.