July 7, 2026

Mobile IOS Developer

Senior • Remote

20,000 - 24,000 PLN

Warsaw, Poland

Salary: 1000 - 1200 PLN/day on B2B

Remote: 100% 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:

  • Integracja i rozwój komponentów reklamowych: Implementacja nowych formatów reklamowych (np. wideo, display, native ads) bezpośrednio w głównej aplikacji

  • 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.

 

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Gdansk, Poland

10,000 - 18,000 PLN

🏢 Summary: B2B role for an experienced .NET Developer to build and modernize a marketing platform that aggregates customer data and supports targeted campaigns, contests, and promotional activities. The position involves maintaining legacy on-premise systems and contributing to frontend improvements while ensuring performance and scalability. Hybrid work model with one day per week in the office. 🗂️ Requirements: Strong experience with .NET Framework 4.8, Good knowledge of .NET Core, Experience with legacy systems, Experience with on-premise applications, Solid knowledge of HTML, Solid knowledge of CSS, Solid knowledge of Bootstrap, Ability to work independently, Experience with .NET MVC 📃 Skills: .NET, C#, ASP.NET, MVC, .NET, Bootstrap, HTML, CSS, React 🏢 Description: Salary: 500 - 900 PLN/day on B2B Work model: hybrid from Gdańsk / Warsaw / Rzeszów / Kraków (1 day per week from the office) Why choose this offer? You can expect a flexible work organization The international work environment will give you the opportunity to interact with the English language on a daily basis The Jit community will bring you a nice time during regular integration meetings Project The project focuses on the development of a marketing platform that aggregates customer data from multiple brands and uses it to design and execute targeted campaigns. The system enables the creation and management of promotional activities such as contests, lotteries, and customer engagement campaigns. Additionally, the project includes smaller initiatives related to hosting and managing clients’ websites, providing a comprehensive approach to supporting their online presence. Responsibilities you'll have Develop and maintain a marketing platform built on .NET Framework 4.8 and .NET Core Work with and gradually improve legacy systems , including on-premise applicationsImplement and enhance features related to marketing campaigns, contests, and user engagement Collaborate on smaller projects involving website hosting and client site management Contribute to frontend improvements using HTML, CSS, and Bootstrap Take ownership of tasks and deliver solutions independently Identify opportunities for system improvements and modernization Ensure stability, performance, and scalability of the platform Expected competences and knowledge Strong experience with .NET Framework 4.8 (must-have) Good knowledge of .NET Core Experience working with legacy systems and on-premise applications Solid understanding of HTML, CSS, and Bootstrap Ability to work independently and proactively manage tasks Problem-solving mindset and willingness to take on technical challenges Nice to have: Experience with .NET-based CMS Basic or practical knowledge of React Technologies you'll work with .NET MVC/.NET Core Bootstrap React Client – why choose this particular client from the Jit portfolio? DOPE Studio is an independent digital agency that combines the capabilities of a creative agency, a strategic consultancy, and a technology provider. The company focuses on delivering data-driven, optimized, and high-performing digital experiences, helping clients solve complex marketing and business challenges. The agency specializes in areas such as digital marketing strategy, web and e-commerce development, content production, SEO, marketing automation, and customer loyalty solutions. It leverages data, technology, and creativity to design engaging campaigns, personalized user experiences, and innovative digital products. 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.

Technology

Jit Team

Danfoss - Lead Frontend Developer

Senior

Remote

Rzeszow, Poland

25,000 - 29,000 PLN

🏢 Summary: Lead Frontend Developer role focused on stabilizing and further developing a complex React-based application integrated with hardware devices via a proprietary communication protocol. The position involves cross-platform development (web, desktop with Electron, embedded), code refactoring, and architectural decision-making in a highly complex technical environment. The role requires close collaboration with backend and hardware teams and contribution to system architecture. 🗂️ Requirements: Very strong experience as Lead Frontend Developer, Advanced knowledge of React, Advanced knowledge of JavaScript, Experience with Electron, Experience integrating applications with hardware or devices, Understanding of cross-platform systems (web, desktop, embedded), Ability to work with low-level communication protocols, Experience analyzing and refactoring complex systems, Understanding of backend architecture and collaboration 📃 Skills: React, JavaScript, TypeScript, Electron, IoT, Embedded, Protocols, Web, Desktop 🏢 Description: Salary: 1250-1450 PLN/day on B2B Remote: remote / hybrid Rzeszów (2 days from the office per week) Why choose this offer? Development and maintenance of a frontend application based on React and JavaScript Support in stabilizing the existing solution and identifying architectural issues Working with system–device communication (client’s proprietary protocol) Development of a desktop application based on Electron Collaboration with backend and hardware/embedded teams Analysis and refactoring of code shared across web, desktop, and embedded environments Contribution to designing the solution architecture in a cross-platform environment Supporting the team in making technical and architectural decisions Project We are looking for an experienced Lead Frontend Developer to support the team in stabilizing and further developing an existing web application that integrates with hardware via a dedicated network protocol. The project is complex in nature—the application communicates with hardware devices, and part of the codebase has been designed in a universal way, enabling its use across web, desktop, and embedded environments. Therefore, a strong understanding of such systems and experience working at the intersection of software and hardware are essential. Expected competences and knowledge Very strong experience as Lead Frontend Developer Advanced knowledge of React and JavaScript (TypeScript is a plus) Experience working with Electron Experience working with applications integrating with devices / hardware (e.g., IoT, embedded systems, device communication) Understanding of challenges related to cross-platform systems (web / desktop / embedded) Ability to work with more “low-level” system communication logic (proprietary or similar protocols) Experience in analyzing and refactoring existing, complex systems Good understanding of backend (in terms of collaboration and architecture) Ability to work in a highly complex technical environment Technologies you'll work with React JavaScript TypeScript Electron Client – why choose this particular client from the Jit portfolio? Our Client engineers technologies that enable the world of tomorrow to do more with less. They meet the growing need for infrastructure, food supply, energy efficiency and climate-friendly solutions . Their products and services are used in areas such as refrigeration, air conditioning, heating, motor control and mobile machinery. They are also active in the field of renewable energy as well as district heating infrastructure for cities and urban communities. Their innovative engineering dates back to 1933 and today our Client is a world-leader , employing more than 27,000 employees and serving customers in more than 100 countries . They are still privately held by the founding family. 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 700 experienced experts . We create highly specialised teams for clients from all over the world. We offer team members developmental projects, a wide range of benefits and a proprietary professional development programme. Behind our maxim are also charitable and educational activities. We support pupils and students by donating learning equipment. We offer internships to help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We are a Polish company and we share what we have achieved over 15 years of activity . By supporting indigenous initiatives, we ensure the circulation of good energy.

Technology

Jit Team

React Native Developer (Mobile)

Senior

Hybrid

Warsaw, Poland

23,100 - 27,300 PLN

🏢 Summary: Hybrid React Native Developer role for a financial services project integrating React Native into an existing native mobile platform (iOS/Android). The position focuses on designing and implementing a seamless brownfield architecture combining React Native and native code. It involves close collaboration with native teams to ensure performance, quality, and robust mobile architecture. 🗂️ Requirements: Strong commercial experience with React Native, Solid experience in native iOS (Swift/Objective-C) and/or Android (Kotlin/Java) development, Proven experience integrating React Native with native platforms (brownfield), Experience designing mobile application architecture, Hands-on experience with native bridges and React Native modules, Experience with REST API integration, Proficiency in English (B2+) 📃 Skills: React, ReactNative, Swift, Objective-C, Kotlin, Java, iOS, Android, Angular, Git, CI/CD, REST 🏢 Description: Salary: 1100 - 1300 PLN/day on B2B Work model: hybrid from Warszawa (2-3 days per week from the office) Why choose this offer? You can expect a flexible work organization The international work environment will give you the opportunity to interact with the English language on a daily basis Scandinavian organizational culture will provide you with work-life balance, you will gain time for additional training (financed by Jit) The Jit community will bring you a nice time during regular integration meetings Project You will work on a financial services project where we are combining React Native output with our existing native platform. This is a challenging integration task that requires strong architectural thinking and a deep understanding of both React Native and native mobile development. The goal is to create a seamless hybrid solution that leverages the strengths of both technologies. Responsibilities you'll have Developing and maintaining React Native modules within a native mobile application Designing and implementing the architecture for integrating React Native with native code (iOS/Android) Working with native bridges and ensuring smooth communication between React Native and native layers Collaborating with native developers to optimize performance and user experience Code review and maintaining high code quality standards Participating in technical discussions and architectural decisions Expected competences and knowledge Strong experience with React Native in production environments Solid knowledge of native mobile development (iOS with Swift/Objective-C and/or Android with Kotlin/Java) Proven experience in integrating React Native with native platforms (brownfield approach) Understanding of mobile architecture patterns and best practices Experience with native bridges and React Native modules Proficiency in English (B2+ level) Nice to have: Experience with Angular (used in related web platforms) Knowledge of CI/CD pipelines for mobile applications Familiarity with financial/banking applications Experience with mobile performance optimization Understanding of mobile security best practices Technologies you'll work with React Native Native technologies: Swift/Objective-C (iOS) and/or Kotlin/Java (Android) Angular (web components) Git, CI/CD tools RESTful APIs Client – why choose this particular client from the Jit portfolio? Jit Team has had an over-decade-long relationship with the leading financial group in the Nordic countries, and we are privileged to be our client's premier partner in Poland. At present, over 200 Jit personnel are engaged in the completion of more than 60 projects for this Norwegian major provider of financial services with a global presence and a strong focus on modern technology. Our customer's work atmosphere is epitomized by the Scandinavian culture , which is conducive to people who place emphasis on work-life balance and feedback culture . Furthermore, all projects are executed in international teams, giving constant exposure to the English language. 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 700 experienced experts . We create highly specialised teams for clients from all over the world. We offer team members developmental projects, a wide range of benefits and a proprietary professional development programme. Behind our maxim are also charitable and educational activities. We support pupils and students by donating learning equipment. We offer internships to help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We are a Polish company and we share what we have achieved over 15 years of activity . By supporting indigenous initiatives, we ensure the circulation of good energy.

Technology

Jit Team

Python FullStack Developer

Senior

Remote

Warsaw, Poland

22,000 - 26,000 PLN

🏢 Summary: Hybrid B2B role for a Python developer focused on building scalable applications, APIs, microservices, and AI-driven data transformation solutions in an international financial environment. The position involves developing integrations, CI/CD pipelines, and automation solutions using modern cloud and AI technologies. Candidates will collaborate closely with product and architecture teams while working with data enrichment, LLMs, and enterprise systems. 🗂️ Requirements: Advanced Python development, Advanced Flask or similar framework knowledge, Advanced REST API knowledge, Intermediate LLM experience, Intermediate Docker experience, Intermediate JavaScript knowledge, Intermediate PostgreSQL knowledge, SQLAlchemy knowledge, Experience with CI/CD pipelines, Experience with Git, Ability to write tests with pytest, Experience with data integrations and transformation, English communication skills, Hybrid availability in Gdynia, Gdańsk, Warszawa, or Łódź 📃 Skills: Python, Flask, REST, LLM, Docker, JavaScript, PostgreSQL, SQLAlchemy, React, CSS, SCSS, pytest, CI/CD, Git, TypeScript, Redux, Zustand, SharePoint, Artifactory, JFrog, Kubernetes, AWS 🏢 Description: Salary: 1100-1300 PLN/day on B2B Work model: hybrid from Gdynia / Gdańsk / Warszawa / Łódź (2/3 days per week from the office) Why choose this offer? You can expect a flexible work organization The international work environment will give you the opportunity to interact with the English language on a daily basis Scandinavian organizational culture will provide you with work-life balance, you will gain time for additional training (financed by Jit) The Jit community will bring you a nice time during regular integration meetings Project We are looking for a forward leaning developer to work closely with Product Owners, Solution Architects and Analysts to refine epics, user stories and business requirements into technical design and working software, with high development standards and to implement some of the industry best practices. Key topics in scope include data transformation as well as AI driven data enrichment, where the overall solution objective is to overlook that all parties involved act according to rules and regulations. And importantly, that this is done as efficiently as possible using modern ways of automation, including but not limited to AI. This involves building data integrations and data transformation logic, reading from and writing to various databases and APIs, securing data completeness and data reconciliations, building microservices and deployment pipelines, and utilizing LLMs both in the actual solutions (e.g. data enrichment) and for support in your role as developer. Responsibilities you'll have Develop and maintain scalable applications, APIs, and microservices using Python and modern frameworks. Collaborate with Product Owners, Architects, and Analysts to transform business requirements into technical solutions. Build and optimize data integrations, transformation processes, and AI-powered data enrichment capabilities. Ensure data quality, consistency, and reliability across databases, APIs, and enterprise systems. Develop and maintain CI/CD pipelines, automated tests, and deployment processes. Support the adoption of AI, automation, and engineering best practices to improve business processes and software quality. Work closely with stakeholders in an international environment to deliver efficient and innovative solutions. To succeed in this role, we believe that a candidate: is a team player who enjoys collaboration in a multicultural environment has a genuine interest to learn and develop within the area is appreciated for your positive approach and ability to turn challenges in to opportunities is good at engaging stakeholders at different levels is a skilled engineer at heart with passion for developing solutions and take pride in seeing your efforts paying off in form of a great business application Expected competences and knowledge Advanced knowledge in Python development and configuration Advanced knowledge of Flask (or similar) frameworks Advanced knowledge of REST APIs Intermediate LLM experience Intermediate Docker experience Intermediate JavaScript experience Intermediate knowledge of PostgreSQL and SQLAlchemy Familiarity with React Familiarity with CSS and SCSS Ability to write tests (preferably with pytest) Experience with CI/CD and creating pipelines Experience with Git Technologies you'll work with Experience with AI tooling Familiarity with TypeScript Familiarity with web components Familiarity with Redux/Zustand Experience with SharePoint API Experience with Artifactory (JFrog) Experience with Kubernetes Experience with cloud services (AWS) Client – why choose this particular client from the Jit portfolio? Jit Team has had an over-decade-long relationship with the leading financial group in the Nordic countries, and we are privileged to be our client's premier partner in Poland. At present, over 200 Jit personnel are engaged in the completion of more than 60 projects for this Norwegian major provider of financial services with a global presence and a strong focus on modern technology. Our customer's work atmosphere is epitomized by the Scandinavian culture , which is conducive to people who place emphasis on work-life balance and feedback culture . Furthermore, all projects are executed in international teams, giving constant exposure to the English language. 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.