Senior React Native Developer

About us

Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer‑led products, and we’re always looking for passionate individuals to join us.

At Ruby Labs we’re looking for a Senior React Native Developer to join our growing engineering team and help lead our expansion into mobile. This is a role for someone who cares deeply about product quality, enjoys solving architectural challenges, and wants ownership over real features that users rely on.

You’ll play a key role in building and scaling our mobile applications, shaping the future of our mobile offering, and collaborating closely with backend and product teams to deliver a seamless, reliable, and high‑performance user experience.

• Contribute to the development and delivery of new mobile product features.
• Maintain and improve the existing React Native codebase, performance, and stability.
• Define and evolve mobile architecture, system design, and technical strategy.
• Partner with backend, product, and design teams to shape solutions that scale.
• Drive reliability, performance, and observability standards on mobile.
• Own production debugging, incident investigation, and root cause analysis.
• Guide improvements in build systems, CI/CD, releases, testing, and app store deployments.
• Support hiring and help grow a world‑class mobile engineering team.
• Champion performance across rendering, navigation, latency, memory, offline behavior, caching, and real‑time experiences.

• 5+ years of experience building mobile applications, with significant React Native experience.
• Experience mentoring engineers through code reviews, architecture, and incident response is a strong plus.
• Strong understanding of mobile system design, component architecture, state management, navigation patterns, and performance trade‑offs.
• Experience optimizing UI performance, memory usage, rendering efficiency, and startup time.
• Deep knowledge of React internals and rendering behavior (hooks, reconciliation, lifecycle, render cost).
• Experience working with native modules and iOS/Android bridging.
• Shipped and maintained apps on the App Store and Google Play.
• Experience with CI/CD, builds, release automation, and OTA updates (EAS, Code Push, or similar).
• Experience implementing monitoring and observability (Sentry, Open Telemetry, crash reporting, performance tracing).
• Demonstrated ownership of edge cases, distributed failure modes, degraded APIs, offline sync, and recovery UX.
• Demonstrated ability to lead architecture or technical strategy for a mobile app or major feature.
• Maintains high standards for clean code, SOLID principles, maintainability, and documentation.

• Experience in startup or high‑ownership product teams.
• Experience scaling real‑time or multi‑region mobile architectures.
• Experience designing or building design systems, shared component libraries, or mobile platform foundations.
• Experience improving mobile security, analytics, performance profiling, and release automation.
• Knowledge of edge caching, streaming real‑time events, Web Sockets, or offline‑first architectures.

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

• Remote Work Environment:
  Embrace the freedom to work from anywhere, anytime, promoting a healthy work‑life balance.
• Unlimited PTO:
  Enjoy unlimited paid time off to recharge and prioritize your well‑being, without counting days.
• Paid National Holidays:
  Celebrate and relax on national holidays with paid time off to unwind and recharge.
• Company‑provided Mac Book:
  Experience seamless productivity with top‑notch Apple Mac Books provided to all employees who need them.
• Flexible Independent Contractor Agreement:
  Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax…