Junior React Native Expo Engineer (hybrid work in Kosice / Krakow / Prague)

DOU Polska; Kraków; Hybrid; PLN 65,000 - 100,000; Full time

Benefits offered by this job

Hybrid work model

Office in Kraków

Job summary

DOU Polska is looking for a Junior Frontend Engineer focused on React Native Expo to join our team in a hybrid setup. You will work on a Real-time micromobility and logistics ecosystem, bridging mobile frontends with Python services powering the logic.

You’ll contribute to mobile-first frontend architecture, admin panels, and scalable backend interfaces, with 60fps performance goals and offline-ready capabilities. English communication required in a fast-paced environment.

Qualifications

• Commercial experience with React Native (Expo).
• Advanced proficiency in React Native Expo.
• Expert-level TypeScript experience with advanced types and strict configurations.
• Deep knowledge of React 18+ fundamentals: hooks, context, memoization, rendering performance.
• Strong knowledge of state management tools (Redux, MobX, Zustand, etc.).
• Experience building map-based UI: react-native-maps / MapView, markers, polylines/routes, camera control, clustering.

Responsibilities

• Architect and scale our React-based mobile web application with a mobile-first approach.
• Build dense, data-heavy Admin Panels for real-time logistics monitoring and dispatching.
• Design and maintain performant APIs using Python (FastAPI/Django) to handle high concurrency.
• Own feature lifecycles from database schema to CSS transitions.

Skills

React Native Expo

TypeScript

React Navigation

Maps / react-native-m maps

Redux / MobX

WebSockets

Firebase

API integration (REST/GraphQL)

GPS / live tracking

Tools

Expo SDK 52+

react-native-maps

Firebase

Job description

We’re looking for a Junior Frontend (React Native Expo) Engineer to join our team.

Work Location: Poland (Krakow), Slovakia (Kosice) or Czechia (Prague).

Hybrid: 2+ days per week in the office, the rest remote.

The Mission

We are building a complex, real-time ecosystem for micromobility and logistics systems sim—where split-second logistics meet seamless user experiences. We need a Junior React Native Expo Engineer to work on our Customer Mobile Web App and our high-utility Internal Admin Panels.

You’ll be the bridge between the sleek, high-performance interface our users see and the robust, scalable Python services that power the logic.

Key Responsibilities

Mobile-First Frontend: Architect and scale our React-based mobile web application, ensuring 60fps performance and offline-first capabilities.

Operational Control Centers: Build dense, data-heavy Admin Panels that allow our operations team to monitor real-time logistics, manage users, and handle complex dispatching.

Scalable Backend: Design and maintain performant APIs using Python (FastAPI/Django) to handle high-concurrency event streams.

End-to-End Ownership: From database schema design to CSS transitions, you’ll own the entire feature lifecycle.

Who You Are

The Architect: You don’t just “write code”; you design systems. You understand how a change in a Python microservice ripples out to the React frontend.

UX Enthusiast: You understand that an Admin Panel requires different UX “muscle” (efficiency and density) than a mobile app (simplicity and speed).

Problem Solver: You’ve dealt with the "hard stuff”—real-time GPS tracking, race conditions in booking logic, or complex state management.

Pragmatist: You balance the need for clean, tested code with the reality of shipping features in a fast-paced environment.

Will be a plus: Led transformation of standalone product into scalable SaaS platform.

Why Join Us?

Work on a product with immediate, real-world impact.

A “no-red-tape” environment where your architectural decisions stick.

Layer Technology

Frontend — React Native Expo, Styled Components, Mobx/Redux, WebSockets. Experience with Firebase, Expo SDK, Expo Modules.

Backend- Python (FastAPI / Django / Flask).

Database — PostgreSQL, Redis (for real-time caching)

Infrastructure — AWS/GCP, Docker, Kubernetes

Real-time- WebSockets / Socket.io (for “Uber-style” live tracking)

Requirements & Skills

• Commercial experience with React Native (Expo)
• Advanced proficiency in React Native Expo.
• Expert-level TypeScript experience with advanced types and strict configurations;
• Deep knowledge of React 18+ fundamentals: hooks, context, memoization, rendering performance.
• Strong knowledge of state management tools (Redux, MobX, Zustand, etc.);
• Experience building map-based UI: react-native-maps / MapView, markers, polylines/routes, camera control, clustering.
• Strong UI implementation skills: different screen sizes, accessibility basics.
• Hands-on experience with GPS / background location tracking
• Expertise in navigation: React Navigation (deep linking, nested navigators, modal flows).
• API integration: REST/GraphQL consumption, request caching, pagination, retries, error handling.
• Handling auth flows (JWT/OAuth), token refresh, secure storage patterns (Keychain/Keystore concepts).
• Core responsibilities:
• Full end-to-end ownership of the mobile app (iOS & Android)
• App maintenance, releases, production stability & incident handling
• GPS / geolocation + live tracking
• REST API + real-time event integration
• Performance, reliability, and architecture improvements
• Ability to understand business requirements and translate them into technical requirements.

Required Skills

• React Native Expo, Styled Components, Mobx/Redux, WebSockets.
• Experience with Firebase.
• Expo SDK 52+, Expo Modules

Language skills

English: Upper intermediate (B2)