iOS Developer Internship – 6 months - Paris - F/H

  • Paris
  • Stage
  • Date de début : 08 décembre 2025
  • Postuler

À propos

Founded in 2014, Karos is the European leader of carpooling for daily commutes. By changing at scale the way people commute, Karos is a major actor of the ecological transition.

The company now operates public carpooling services for more than 100 local authorities and 600 employers, with over 1.5 million users and rollouts across 6 European countries.

Since 2024, Karos is a mission-driven company (French “Société à mission”).

Our mission, written into our bylaws:

We are creating a new way of carpooling that is desirable and efficient, wherever it is useful, in order to improve everyday life and accelerate the ecological transition. As a trusted partner of key players in the territories, we are fighting to make carpooling a new standard for everyday transport.

Our impact is greatest where alternatives are lacking: daily commutes by private car.

It is on these trips — mainly home–work, peri-urban and rural — that we are committed, working with public and private stakeholders to change habits at scale.

Today, we are 100 team members, mainly based in France and Germany, and we are rapidly expanding across Europe (🇫🇷 🇩🇪 🇪🇸 🇨🇭 🇮🇹 🇳🇱).

Descriptif du poste

Descriptif du poste

Are you passionate about iOS development and eager to build real features with an experienced team? Join Karos for a 6-month internship (Starting between December 2025 and March 2026) and help us evolve our iOS app — connecting thousands of daily carpoolers and accelerating the shift toward sustainable mobility.

Your mission

Under the guidance of our Mobile team, you will:

  • Develop and refine user interfaces using SwiftUI, with a strong focus on performance, design fidelity, and accessibility.

  • Write and maintain unit and UI tests to ensure code quality and reliability.

  • Contribute to architectural decisions, refactoring, and continuous codebase improvement.

  • Collaborate closely with backend, design, and product teams to ship impactful updates to real users.

  • Learn and apply best practices in Swift, SwiftUI, and testing frameworks, while contributing to the continuous improvement of our mobile stack.

Profil recherché

What we’re looking for

  • Final-year Master’s student in Computer Science or related field.

  • Strong foundation in Swift and iOS fundamentals (UIKit, SwiftUI, Combine, etc.).

  • Interest in modern iOS design patterns and scalable app architecture.

  • Familiarity with unit testing (XCTest, snapshot testing).

  • Curiosity, autonomy, and eagerness to learn from senior engineers and build for real users.

  • Collaborative mindset and curiosity for mobile architecture and performance optimization.

  • Bonus: experience with CI/CD (GitHub Actions, Fastlane) or API integration.

What you’ll gain

By joining Karos, you’ll take part in real-world app development and learn how to deliver features from design to App Store.

  • Hands-on experience in a fast-paced, mission-driven startup.

  • Mentorship from senior iOS developers and product designers.

  • Deep dive into SwiftUI and modern testing tools.

  • The opportunity to build and ship features used daily by thousands of users.

  • Insight into how technology can drive sustainable mobility and reduce carbon impact.

Additional Information 🚗🌱

  • A warm, inclusive, and supportive team

  • Offices centrally located in Paris and easily accessible

  • 💚 At Karos, we believe short-distance carpooling can become a new form of public transport — and we’re building it together.

    Join us to create a sustainable mobility future.

Process de recrutement

  • Initial interview — Get to know our iOS Tech Lead & Mobile Engineering Manager and share your background and goals.

  • Technical interview — Explore Swift, SwiftUI, and testing concepts through practical discussions.

Informations complémentaires

  • Type de contrat : Stage (6 à 6 mois)
  • Date de début : 08 décembre 2025
  • Lieu : Paris
  • Niveau d'études : Bac +5 / Master
  • Expérience : < 6 mois
  • Télétravail ponctuel autorisé