About Us: We are a manufacturer of photovoltaic inverters. In addition to our hardware products, we offer digital tools such as mobile apps to enable modern commissioning, monitoring, and analysis of PV systems for our customers and installers. These digital solutions are not an end in themselves, but an essential part of our overall product offering, allowing us to remain competitive, market-oriented, and customer-focused.
For further development of our Engineering Center, we are looking for Senior Mobile App Developer(Android & iOS)
Your Responsibilities Technical Ownership & Maintenance — Assume end-to-end technical ownership of an existing Android and iOS app — Maintain, analyse, and evolve an organically grown legacy codebase — Work pragmatically with technical debt and historically evolved architectures — Evaluate, prioritise, and execute refactoring initiatives Cross-Platform Development (Kotlin Multiplatform + Native) — Extend shared modules built with Kotlin Multiplatform (KMP) — Maintain and enhance native code: Android: Kotlin, Android SDK, Jetpack iOS: Swift, SwiftUI / UIKit — Enforce clear separation between shared and platform-specific layers — Ensure robust, stable interfaces between KMP and native components App Lifecycle, Releases & Stores — Own the full app lifecycle on both platforms — Publish, maintain, and update apps in: Google Play Apple App Store — Plan and deliver: o Feature releases o Maintenance and bug-fix releases o Emergency hotfixes — Navigate store guidelines, review processes, and app rejections Quality, Testing & Monitoring — Safeguard app stability, performance, and security — Plan, implement, and maintain automated tests (unit, integration, UI) for Android and iOS — Champion test-driven development (TDD) where it adds value — Integrate and operate: o Crash reporting (e.g. Crashlytics) o Analytics o Monitoring tools — Analyse user feedback, support tickets, and store reviews to drive improvements — Continuously raise code quality and product reliability UI/UX & Design Collaboration — Partner with designers to create intuitive, user-friendly experiences aligned with UI/UX best practices Collaboration, Knowledge Transfer & Mentoring — Serve as a technical point of contact for internal teams and external partners — Lead the transition of knowledge from external to internal teams — Build and maintain concise technical documentation — Improve internal development processes and standards — Mentor and onboard junior team members; proactively share knowledge Your Profile Must-haves / What Matters Most — 5+ years of professional experience in mobile app development — Strong expertise in: o Android: Kotlin, Android SDK, Jetpack o iOS: Swift, SwiftUI and/or UIKit — Proven experience with Kotlin Multiplatform or similar shared-code approaches — Passion and skill in handling: o Legacy code o Refactoring o Incremental modernisation — Ability to realistically assess and prioritise technical debt — Focus on long-term maintainability and platform health, not just feature delivery — Solid understanding of REST APIs and authentication — End-to-end experience publishing to Google Play and the Apple App Store — Solid experience with automated testing frameworks (e.g. Espresso, XCTest, kotlin.test) and/or strong command of TDD — Familiarity with UI/UX principles and effective collaboration with designers — Hands-on experience with Firebase Crashlytics (crash reporting) and monitoring tools — Independent, structured, and accountable working style Nice to Have — Experience with Coroutines, Flow, Ktor Client — Experience with Compose and/or Compose Multiplatform — Familiarity with SQLDelight or multiplatform persistence solutions — Domain knowledge in photovoltaics, energy, IoT, or monitoring — Familiarity with CI/CD for mobile apps — Experience with analytics tools (e.g. Firebase Analytics, Amplitude, Mixpanel) — Experience collaborating with external development partners — Basic knowledge of Angular or similar web frameworks — Knowledge of mobile app security best practices (e.g. secure data storage, encryption, secure APIs) — Pragmatic, solution-oriented mindset — High sense of ownership, responsibility, and reliability — Motivation to contribute to sustainable technologies — Strong communication and teamwork skills — Willingness to learn, share knowledge, and support others
We offer: * Paid vacation and sick leave; * Flexible schedule; * Stable and competitive salary; * Continuous training process and exchange of experience within the company and with foreign colleagues.
