Senior React Native Developer

👋 Who are we?

We’re The Widlarz Group, a software house specializing in React Native, actively contributing to the Open Source community. You might already know our work - we’re the team behind popular Open Source libraries like react-native-video.

Our teams - especially the Special Task Force - specialize in performance audits, technical debt assessments, recovery plans, and R&D in the area of native libraries.

We value transparent communication, a shared pursuit of excellence, and the real impact of every team member on our organization’s growth - principles we developed together and live by every day.

We’re building a community, not just a team. We want our collaborators to feel part of something bigger - we co-create projects, contribute to open source, and meet regularly to share knowledge and experience.

We work remotely, but meet weekly in Kraków to share knowledge, plan ahead, and keep our team culture strong.

🛠 What will you do?

• Audit React Native apps, propose solutions to reduce technical debt, improve performance, and implement monitoring.
• Develop advanced mobile applications in React Native, including video-related projects.
• Build custom solutions for clients and contribute to our OSS projects, including react-native-video, rn-emoji-keyboard, and react-native-notificated.
• Implement and actively help build our own tools as well as open source ones.
• Work with our Special Task Force on app audits, performance optimization, and implementing innovative solutions.
• Operate in a flat structure where your input genuinely influences project direction.
• Test, debug, optimize code, and implement best practices in React Native.
• Mentor other devs and share your knowledge across the organization. 

✅ What we expect from you?

• 4-5+ years of commercial experience with React Native, including both greenfield projects and legacy systems.
• Proficiency in TypeScript and JavaScript (ES6+), with knowledge of design patterns, clean code principles, and strong typing.
• Experience creating and integrating native modules in React Native for iOS (Objective-C/Swift) and Android (Java/Kotlin).
• Familiarity with native AV libraries (AVPlayer, ExoPlayer) - big plus.
• Strong debugging skills (Flipper, React Native DevTools, Chrome DevTools, Android Studio Profiler, Xcode Instruments) and performance optimization experience (profiling, render time minimization, memory optimization).
• Experience with video-based projects (e.g., player integration, streaming, offline video SDKs) - big plus.
• Solid knowledge of Expo and Bare Workflow, including EAS Build and EAS Update.
• Familiarity with various state management and data handling approaches, including integration with popular backends/cloud services (REST, GraphQL, Firebase), as well as caching, synchronization, and app architecture libraries.
• Experience with building and publishing mobile apps (Google Play, App Store), including CI/CD setup (e.g., Fastlane, EAS, Bitrise, GitHub Actions).
• Ability to write unit and integration tests (Jest, React Native Testing Library, Detox).
• Team collaboration using modern tools (Git, PRs, Code Review, CI/CD), paired with independence and initiative.
• Proactive, communicative attitude and a passion for sharing knowledge - as important to us as technical skills.
• Fluent English (min. B2).
• Willingness to work with clients across different time zones (mainly USA) - flexibility in working hours and availability for meetings.
• Customer-oriented approach and ability to translate business requirements into technical solutions.

🎯 What do we offer?

• Salary: 22,000 – 28,000 PLN net/month B2B (depending on experience and skills).
• Remote work with one day per week in our Kraków office.
• 21 paid days off per year for full-time collaborators - take a relaxing vacation with family or friends.
• Subsidized private health insurance and access to MultiSport.
• Real impact on projects and company strategy.
• Work with top experts - our developers are among the best in React Native and mobile performance.
• Participate in internal audits and Special Task Force - where we solve the toughest tech challenges in the mobile world.
• Access to conferences, courses, and educational materials - we constantly grow our skills.
• Feedback culture and transparent communication based on our Culture Book values.
• Team initiatives - we create space for growth and activities beyond day-to-day coding.

⚙️ Our recruitment process

1. ✅ Short screening survey (~5 min) - quick check of key criteria.
2. 💬 Culture fit interview (30 min) - we ensure our values and work style align.
3. 🔧 Technical interview with our dev team (1.5 h) - with the dev team - we assess your skills and problem-solving approach.
4. 🤝 Offer discussion & agreement (15-20 min) - we wrap things up and get started.

Sounds like a match? Let’s build something exceptional - together.

Click Apply, and we’ll take it from there 🚀