Mobile IOS Developer

Jit Team; gmina Serokomla; Hybrid; PLN 185,000 - 221,000; Part time

Job summary

Jit Team poszukuje Senior Mobile Developera o specjalizacji iOS z kompetencjami JavaScript do projektu w domenie Advertising. Praca wymaga solidnych umiejętności w tworzeniu natywnych aplikacji mobilnych oraz integracji z webowymi treściami reklamowymi.

Oczekuje się doświadczenia w architekturze MVVM/MVI, znajomości WebKit/WKWebView oraz pracy w zwinnych metodach Scrum. Praca z zespołem ds. reklam i dużymi aplikacjami mobilnymi zapewnia styczny kontakt z technologiami AdTech.

Qualifications

• Ponad 5 lat komercyjnego doświadczenia w tworzeniu natywnych aplikacji mobilnych na iOS (Swift).
• Głęboka znajomość architektury aplikacji mobilnych (MVVM, MVI, Clean Architecture).
• Doświadczenie z WebKit oraz WKWebView i komunikacją między kodem natywnym a webowym.

Responsibilities

• Integracja i rozwój komponentów reklamowych: wprowadzanie nowych formatów reklam bezpośrednio w aplikacji.
• Wsparcie Video Ad Stack: optymalizacja odtwarzania reklam wideo i prawidłowe wyzwalanie zdarzeń śledzenia.
• Współpraca między zespołami: zapewnienie zgodności architektury aplikacji i bezpieczeństwa.

Skills

Mobile development

iOS development

JavaScript

Tools

WKWebView

WebKit

RxSwift/RxKotlin

Jetpack Compose

Job description

Salary: 1000 - 1200 PLN/day on B2B

Remote: Poznań (1 day from office, 4 days remote)

Why choose this offer?

• Impact on the development of the largest e-commerce system in Poland
• You can expect a flexible work organization
• Long-term cooperation within a stable ecosystem
• The Jit community will bring you a nice time during regular integration meetings

Project

The engineer assigned to the project should understand the intersection of Native Mobile development and the dynamic AdTech environment. The ideal consultant is someone who recognizes that in-app advertising is not just an "image," but a complex ecosystem built on IAB (Interactive Advertising Bureau) standards.

Performance & UX Mindset

They must be able to balance business objectives (monetization) with user experience, ensuring, for example, that advertising scripts do not block the application's main thread.

Hybrid Developer (iOS Developer with JavaScript knowledge)

The candidate should be comfortable using JavaScript within WebViews to understand why an ad creative may not be reporting events correctly, while still maintaining a strong foundation in the native technology stack.

We are looking for a Senior Mobile Developer to provide project support in the Advertising domain. Your specialist will support a team responsible for the technological aspects of ad delivery and display within mobile application.

Responsibilities

• Integration and development of advertising components: Implementation of new advertising formats (e.g. video, display, native ads) directly within the main application
• Video Ad Stack support: Optimising video ad playback, ensuring smooth transitions and correct triggering of tracking events.
• Cross-team collaboration: Working closely with Core Mobile teams to ensure consistency with the app’s architecture and the highest standards of security and performance.
• Privacy management (Compliance): Implementing and maintaining data privacy solutions, such as GDPR consent management (CMP), and adapting to changes in systems.
• Debugging ‘difficult cases’: Analysing and resolving issues at the interface between the app’s native code and external advertising libraries (SDKs) and web creatives.
• Frontend/Backend support: Actively participating in the design of solutions that require communication between the mobile app and advertising systems.
• Experience working with large-scale, high-traffic mobile apps.
• Knowledge of reactive programming (e.g. RxJava/RxKotlin, Combine).
• Knowledge of Jetpack Compose and coroutines.
• Experience working with A/B testing frameworks.
• Contributions to open-source projects or a strong GitHub profile.
• Experience working in an Agile/Scrum environment

Expected competences and knowledge

• Over 5 years’ commercial experience in developing native mobile applications for iOS (Swift).
• In-depth understanding of mobile application architecture patterns (e.g. MVVM, MVI, Clean Architecture).
• Practical experience with WebKit and WKWebView, including in the area of native-to-web communication (e.g. handling JS messages via WKScriptMessageHandler and invoking JavaScript code).
• Solid knowledge of JavaScript and core web technologies (HTML/CSS) to effectively integrate and debug web-based advertising content.
• Experience working with RESTful APIs, asynchronous programming and efficient data processing.
• Proficiency in writing unit and integration tests.
• Knowledge of version control systems (e.g. Git).
• A solid understanding of software engineering principles, data structures and algorithms.
• A proactive approach to problem-solving and a passion for creating excellent user experiences (UX).

Technologies you’ll work with

• iOS
• Swift
• JavaScript
• WebKit
• REST API

Client – why choose this particular client from the Jit portfolio?

Our Client dominates the Polish e-commerce arena as the market leader since 1999. With a user base of over 20 million and growing, this well-established platform is at the forefront of e-commerce, constantly striving for growth through market expansion and investment. As a major player in technology, our Client boasts a talented IT team of over 1,000 employees who focus on developing their own cutting‑edge technologies.

Jit Team has had a successful partnership with our Client since spring 2021, with multiple software development teams dedicated to our Client's platforms. These teams operate autonomously, designing platform components through micro‑services.

Working with our Client offers a chance to contribute to a solution used by millions on a daily basis and to tackle the challenge of delivering software at a massive scale, where even a single second of delay can have a significant impact. This project provides a unique opportunity to work with state‑of‑the‑art technologies and tools, making it a rare and valuable experience.

About Jit Team

The Human Factor of IT - it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts, to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams.

Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.