Cross-platform Mobile Engineer

Kauri One is a software development company that creates fintech–blockchain projects. We implement the entire range of financial instruments for processing fiat and cryptocurrencies in a single system.

We are currently looking for a passionate Kotlin Multiplatform Developer with Web3 / Crypto / Fintech / Banking experience to join our team.

You can check out more details about the product we're hiring for at this link: https://xono.finance

### About the project

A production fintech app for the EU market, already live on both stores. One Kotlin Multiplatform codebase — ~78,000 lines of Kotlin, **~88% of it shared between Android and iOS**, with a shared UI on Compose Multiplatform — powers **three white-label apps** from a common core plus a thin per-brand shell.

You join a small mobile team that owns the whole thing end to end — architecture, both platforms, store releases.

### What you will work on

- Features in `commonMain`: MVI view models, repositories, Compose Multiplatform screens — plus the Android/iOS `actual` implementations where the platforms genuinely differ.
- Integration with ~11 backend microservices over Ktor, driven by OpenAPI contracts.
- Security-critical work: hardware-backed key storage for the session token, biometric app lock, WebAuthn passkeys (Ory Kratos), Talsec freeRASP threat reactions.
- Bridging native SDKs on both platforms: Tap-to-Pay, Firebase, Sign in with Google/Apple.
- Quality and observability: OpenTelemetry tracing, unit tests, an instrumented end-to-end API suite that runs against a live backend.
- Extracting the shared shell into a reusable internal foundation as the three apps diverge, and setting up mobile CI/CD.

### Tech stack

Kotlin 2.4, Kotlin Multiplatform, Compose Multiplatform 1.12, Coroutines/Flow, Ktor 3, kotlinx.serialization, Koin, Compose Navigation, DataStore, Firebase (Crashlytics, Remote Config, FCM, Analytics), OpenFeature, OpenTelemetry, Tolgee runtime localization, Talsec freeRASP, CameraX, Swift/SwiftUI in the iOS shells, Gradle Kotlin DSL, Xcode.

### Requirements

- 2+ years of commercial mobile development, including hands-on production experience with Kotlin Multiplatform.
- Strong Kotlin: coroutines and Flow, generics, `expect/actual`, multi-module Gradle (Kotlin DSL) builds.
- Solid Compose experience (Compose Multiplatform or Jetpack Compose): state hoisting, recomposition and performance, custom layouts, working inside a design system.
- Layered architecture with unidirectional data flow (MVI/MVVM), DI, code you can actually test.
- Confident with REST/JSON, OpenAPI contracts, auth flows (OIDC/OAuth, session tokens, refresh).
- Able to build, sign and ship the iOS target yourself: Xcode, schemes, provisioning profiles, TestFlight / App Store Connect. Reading-level Swift at minimum.
- English: Intermediate (written communication and documentation).

### Nice to have

- Fintech / banking / crypto domain: payments, wallets, ledgers, KYC/AML.
- Mobile security: Android Keystore / iOS Keychain, biometrics, WebAuthn / passkeys, RASP, certificate pinning.
- Native Swift / SwiftUI development.
- Release ownership: Play Console, App Store Connect, phased rollouts, mobile CI/CD.
- Feature flags, distributed tracing, localization at scale.

### We offer

- [full remote or office]
- [20 paid vacation days, paid sick leave]
- [compensation range, review cycle]