Kotlin Multiplatform Engineer

About the role

We are looking for a strong Kotlin Multiplatform Engineer to join our mobile engineering team and help shape the architecture of the next generation of Wittix products. This is an opportunity to have a direct impact on the architecture of a real‑world platform that combines Kotlin Multiplatform, payments, AI, commerce, hardware, cloud infrastructure, and real‑time systems. You don’t need to have built a banking app before, but you should want to work where correctness matters.

Key responsibilities

• Design and develop production applications using Kotlin Multiplatform.
• Own and evolve the shared KMP architecture across the product suite.
• Build reusable shared modules for domain logic, networking, persistence, authentication, state management, synchronization, error handling and observability.
• Define clear boundaries between shared KMP code and platform‑specific implementations.
• Develop Android‑specific integrations and, when needed, iOS integrations.
• Implement authentication and payment authorization flows, including 3‑D Secure, Google Pay and Apple Pay.
• Build real‑time experiences connected to cloud services and event‑driven back‑ends.
• Apply mobile security fundamentals such as secure key storage, certificate pinning and integrity checks.
• Debug complex production issues across shared and native code.
• Collaborate with Backend, Product, QA and DevOps teams and participate in architectural decisions.

Required profile

• 4+ years of professional mobile development, primarily Android.
• Strong Kotlin skills, including Coroutines and Flow.
• Hands‑on experience with Kotlin Multiplatform shipped to production.
• Understanding of modular architecture and the split between shared and platform‑specific code.
• Experience with REST APIs and local persistence (SQLite/Room or equivalent).
• Ability to read, debug and ship changes in an iOS codebase or a clear appetite to learn quickly.
• Pragmatic architectural decision‑making in a real product.
• Fluent working English.

Required skills

• Kotlin
• Kotlin Multiplatform
• Coroutines
• Flow
• Android development
• Swift (basic proficiency)
• iOS development concepts
• REST APIs
• SQLite / Room
• 3‑D Secure payment flow
• Google Pay integration
• Apple Pay integration
• Secure key storage
• Certificate pinning
• Device and app integrity checks