Senior Mobile Engineer (Swift and/or Kotlin)

Exerizon

5d • Remote

About The Position

Exerizon is a fast-growing strategy and technology consulting firm founded by former senior leaders from global consulting and cloud organizations. It helps current and future market leaders with digital strategy, cloud transformation, data and AI platforms, and application modernization. The firm uses impact-based remuneration and shares ownership with employees from day one.

The Senior Mobile Engineer builds and modernizes native mobile apps for clients in banking, insurance, and healthcare. The apps may serve as clients’ primary customer channel and operate under high-traffic, security, and regulatory requirements. The role can focus on iOS using Swift, Android using Kotlin, or both. It includes technical ownership, client collaboration, mentoring, and contributing to Exerizon’s mobile practice.

Requirements

• At least 6 years of native mobile development, including at least 3 years with Swift for iOS and/or Kotlin for Android.
• At least two apps shipped to production and maintained through multiple releases.
• Deep knowledge of the relevant platform: for iOS, SwiftUI and UIKit, Swift Concurrency or Combine, and the Xcode toolchain; for Android, Jetpack Compose, Kotlin Coroutines and Flow, Android Jetpack, and Gradle.
• Working understanding of the other mobile platform.
• Hands-on mobile security experience in regulated environments, including OAuth2/OIDC, strong customer authentication flows, secure storage, certificate pinning, OWASP MASVS, and remediation of penetration-test findings.
• Experience with testing and CI/CD, including XCTest or JUnit, UI and snapshot tests, automated pipelines, code signing, store submission, and release management.
• Ability to own architecture decisions and safely refactor large legacy codebases, with measurable improvements such as build time, crash rate, or release cadence.
• Experience designing or integrating a server-driven UI framework, including component schemas, a client renderer, schema versioning, and A/B-tested layouts; understanding of SDUI trade-offs involving offline support, performance, and accessibility.
• Daily use of AI-driven development tools, understanding of their failure modes, and ability to review AI-generated code to the same standard as personally written code.
• Fluency in REST and GraphQL API integration, 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 such as PSD2/SCA and GDPR.
• Clear communication with non-engineers, including explaining trade-offs to product owners and providing honest estimates.
• Full professional fluency in Polish and English.

Nice To Haves

• Mobile payments integration, such as Apple Pay, Google Pay, or BLIK.
• Accessibility auditing experience with VoiceOver or TalkBack.
• Tech lead or team lead experience on a client-facing engagement.
• Experience building team AI tooling, such as custom agents, MCP servers, or codebase-specific skills and prompts.
• Experience shipping an SDUI-based app at scale or contributing to an open-source SDUI framework.

Responsibilities

• Design and build native iOS apps in Swift with SwiftUI and UIKit, and/or Android apps in Kotlin with Jetpack Compose, including new features, modernization, and justified rewrites.
• Own platform architecture, including modularization, MVVM, Clean Architecture or TCA, dependency injection, offline-first approaches, and data synchronization.
• Design and evolve server-driven UI, including component schemas with backend teams, client-side rendering, schema versioning, backward compatibility, and graceful fallbacks.
• Use AI coding agents and copilots for implementation, refactoring, test generation, and code review; verify their output and help bring effective practices to the team.
• Integrate backend services and secure applications end to end.
• Set and enforce engineering standards for reviews, testing, CI/CD, signing, and App Store and Google Play release management, including phased rollouts.
• Build observability and product quality capabilities, including crash reporting, analytics, feature flags, and performance and startup-time budgets.
• Deliver accessibility and localization to the standards required by regulated clients.
• Work directly with client product owners, designers, backend engineers, and QA; estimate, plan, and demonstrate work to stakeholders.
• Mentor mid-level engineers and contribute to Exerizon’s mobile practice, proposals, and pre-sales demonstrations.

Benefits

• Real ownership of the apps built and direct contact with client product owners.
• Competitive compensation on a B2B contract.
• Annual training and certification budget.
• Remote work model with access to a central Warsaw office.
• Opportunity to shape the firm’s mobile practice, engineering standards, hiring, and culture.

What This Job Offers

• Career Level: Senior
• Education Level: No Education Listed