(Senior) Full Stack Engineer (Backend Focus) (m/f/d) in Karlsruhe

Chrono24 is the world's leading marketplace for luxury watches. In Buyer Experience, our Loyalty team makes sure buyers don't just purchase once but keep coming back. We're a cross-functional team of product management, UX, QA and engineering that owns its product area end to end.
What you'll do

• Build the features that keep buyers coming back, such as Watch Collection, Wishlist, and the user account.
• Work closely with product management and UX: challenge product ideas, propose simpler solutions, and bring your technical expertise together with their product expertise.
• Design and build backend services and APIs with Java and Spring, implement the frontend changes a feature needs, and keep it all reliable in production.

• A platform used by millions of watch enthusiasts worldwide, with the reach of an established marketplace and the short decision paths of a small team.
• Open discussions about quality and trade-offs, where good arguments count for more than hierarchy.
• Java 25, Spring, MySQL; Vue.js, Jetpack Compose, and SwiftUI across web, Android, and iOS; GitLab CI; AI tools like Claude Code in our daily workflow.
• 10% of your working time reserved for learning or personal projects.

You…

• Think in terms of the problem, not the ticket, and care whether a feature actually makes a difference for buyers.
• Write code that others can read, change, and trust.
• Are most at home in the backend, but don't stop at the API when a feature needs frontend changes.
• Use AI tools like Claude Code every day and review their output as critically as you would a colleague's code. Experience in setting up and improving an agentic coding environment is a plus.
• Enjoy a good debate: you challenge ideas, including ours, and commit once a decision is made.
• Value pragmatism over purity and can tell "good enough for now" from "this will hurt us later."

You bring hands-on experience with:

• Java and its ecosystem, including testing, CI/CD, and how software runs in production, and some of the tools we use (Spring, Maven or Gradle, SQL, GitLab).
• Frontend development on at least one of our platforms: web (Vue.js), Android (Jetpack Compose), or iOS (SwiftUI). You don't need to be a specialist, but you can build and change UI features confidently.

• We only offer permanent employment contracts.
• 30 days of vacation per year.
• Working from HQ in Karlsruhe? Our kitchen conjures up a truly excellent, free meal for you every day.
• On December 24th and 31st, we’ll give you an additional day off.
• Work abroad for up to 20 days per year: Working with a sea view? Yes, please!

Diversity is our strength.
At Chrono24, we embrace diversity because we believe it enriches not only our corporate culture but also our success. Be yourself – and let’s achieve great things together!