Backend Engineering Intern

In short

Whether you’re looking to jump start your career or gain first hands-on experience in a new field, an internship at On offers you a unique growth experience, the chance to make an impact from day 1 and contribute to On’s growth journey. We are looking for fresh ideas, curious minds and passionate individuals ready to make a difference. Our internships generally last 6 months and you will be fully embedded in a team.

• Start date: ADD DATE (Sept 1 or March 1)
• Duration: 6 months
• Prerequisite: Interest in area relevant to the internship, passion for On, right to work in EU / Switzerland
• Note: This is a paid internship
• If you don't meet the criteria above, unfortunately, we cannot move forward with your application. Please be truthful in your answers, the recruiter reviewing your application will appreciate your honesty.
  
  

Curious about life as an intern at On? We recommend watching the recording of our previous livestream (https://www.careerfairy.io/company/On_AG/livestream/eCaoLI8t0mYLqzRYM1eq) to hear former interns share their internship experience, get an insider’s look at different departments and pick up some tips and tricks from our recruiters to help you ace the application process! Please note that the next internship program kicks off on March 1 (not September 1 as mentioned in the livestream).

Your mission

Are you excited about learning how scalable backend systems are built and how data powers global products? Join On’s Product Core Technology team as a Backend Engineering Intern, where you’ll contribute to building the systems that enable our product data to flow across our digital ecosystem — from design and development to ecommerce and marketing. This internship offers a unique opportunity to work on meaningful challenges at the intersection of product data, backend systems, and digital experiences. You’ll be part of a team that builds GraphQL APIs, Kafka-based streaming systems, and backend services that power On’s website, mobile app, and internal platforms. If you’re curious, eager to learn, and ready to grow your backend development skills in a fast-paced and collaborative environment, we’d love to hear from you!

In Your First Month

• Get to know On’s product data landscape, tools, and engineering practices
• Shadow senior engineers and participate in team rituals like stand-ups, code reviews, and pair programming
• Contribute to small tasks or improvements in our services and documentation
  
  

After Three Months

• Help implement new features or improvements to internal tools, APIs, or data flows
• Contribute to the development of backend services in TypeScript and Node.js
• Learn how event-driven systems (e.g. Kafka) are used in large-scale data pipelines
  
  

Beyond

• Own on intern-level projects that improve data visibility, tooling, or developer workflows
• Present what you’ve built to the team and gather feedback
• Take initiative in learning new backend concepts and frameworks used in production systems.
  
  

Your story

• Some experience with backend development — ideally with Node.js and TypeScript (through personal projects, coursework, or previous internships)
• Curious about APIs (especially GraphQL), databases (SQL or NoSQL), and cloud systems
• Eager to learn event-driven architecture and real-world data engineering patterns
• A team player who communicates clearly and enjoys collaborating
• Enthusiastic about data, technology, and building tools that help others
  
  

Bonus Points

• You’ve built or contributed to a backend or data-related project (personal, academic, or open-source)
• Git, tooling and deployment patterns
• Interest in how products are developed and brought to market
• A passion for sports, technology, or both!
  
  

What We Offer

On is a place that is centered around growth and progress. We offer an environment designed to give people the tools to develop holistically – to stay active, to learn, explore and innovate. Our distinctive approach combines a supportive, team-oriented atmosphere, with access to personal self-care for both physical and mental well-being, so each person is led by purpose.

On is an Equal Opportunity Employer. We are committed to creating a work environment that is fair and inclusive, where all decisions related to recruitment, advancement, and retention are free of discrimination.