Senior Mobile Engineer – Swift, Kotlin

• Design and build native apps in Swift (SwiftUI, UIKit) and/or Kotlin (Jetpack Compose), including new features, legacy modernisation and justified rewrites
• Own platform architecture, including modularisation, MVVM / Clean Architecture / TCA, dependency injection, offline-first and data sync strategies
• Build and evolve server-driven UI (SDUI), including component schemas, client-side rendering, schema versioning, backward compatibility and graceful fallbacks
• Practise AI-driven development using coding agents and copilots for implementation, refactoring, test generation and code review
• Integrate backend services through REST, GraphQL and gRPC, and secure apps end to end
• Set and enforce engineering standards covering code review, unit/UI/snapshot testing, CI/CD, signing and app-store release management with phased rollouts
• Build observability and product quality through crash reporting, analytics, feature flags, performance and startup-time budgets
• Deliver accessibility and localisation for regulated clients
• Work with client product owners, designers, backend engineers and QA; estimate, plan and demo work to stakeholders
• Mentor mid-level engineers, raise Exerizon’s mobile practice standards, and support proposals and pre-sales demos

• 6+ years of native mobile development, including 3+ years in Swift (iOS) and/or Kotlin (Android); at least two apps shipped to production and maintained through multiple releases
• Deep knowledge of your platform — iOS: SwiftUI and UIKit, Swift Concurrency or Combine, Xcode toolchain; Android: Jetpack Compose, Kotlin Coroutines and Flow, Android Jetpack, Gradle — with a working understanding of the other platform
• Hands-on experience with mobile security in regulated environments: OAuth2 / OIDC and strong customer authentication flows, secure storage, certificate pinning, OWASP MASVS, and closing pen-test findings
• Solid testing and CI/CD practice: XCTest or JUnit, UI and snapshot tests, automated pipelines, code signing, store submission and release management
• Proven ability to own architecture decisions and refactor large legacy codebases safely, with measurable improvements in build time, crash rate or release cadence
• Experience designing or integrating a server-driven UI framework: component schemas, a client renderer, schema versioning and A/B-tested layouts; understanding of where SDUI pays off and where it hurts (offline, performance, accessibility)
• AI-driven development as part of your workflow: daily use of coding agents and copilots, understanding of their failure modes, and review of AI-generated code to the same standard as your own
• Fluent API integration: REST and GraphQL, OpenAPI contracts, and collaboration with backend teams on API design
• Experience delivering apps in banking, insurance, fintech or healthcare, including PII handling and regulatory constraints (PSD2 / SCA, GDPR)
• Clear communication with non-engineers: explaining trade-offs to a product owner and estimating honestly
• Full professional fluency in Polish and English

• Real ownership of the apps you build and direct contact with client product owners — no ten-layer review pyramid
• Competitive compensation on B2B contract
• Annual training and certification budget
• Remote work model with access to a central Warsaw office
• A seat at the table in shaping a young firm: our mobile practice, engineering standards, hiring and culture