Backend Engineer

Within our Core User Profile Team, we are looking to define how ratings should look like and behave to enable trust between buyer/seller and to create the best shopping experience.

This role is based at our Barcelona Tech Hub
, where we develop
cutting-edge technology
to power our marketplaces  part of a cross‑functional product development team, you will contribute to the success of
Kleinanzeigen
, Germany’s leading online classifieds platform with over
36 million monthly users
and
50 million active listings
.

We’re seeking a passionate new team member to join us as a Backend Engineer. This is an excellent opportunity to join one of our Core Marketplace Teams at Kleinanzeigen working with User Profile products. We are looking for a skilled Backend developer to join us; someone who can solve complex engineering problems with a strong user focus and loves to work with passionate and engaged people in one of the world’s leading classifieds platforms.

You will work in an agile and cross‑functional team together with Frontend and Native app Engineers, Backend Engineers, Product Manager and UX experts to enable our customers to have the best experience. You'll collaborate closely with other platform core teams to ensure seamless integration and a cohesive user experience.

• Be part of a welcoming and multicultural team, working in an Agile environment
• Collaborate closely with Backend, Frontend and Mobile Engineers, as well as Product Managers and UX designers
• Develop and maintain high‑quality backend systems applications, scaling to thousands of concurrent requests
• Write clean, efficient, and reusable code following best practices and coding standards
• Participate in design decisions and code reviews
• Own the entire development and release cycle from specification to running in production together with your cross‑functional team
• Ensure the quality of your product because you understand that quality is the responsibility of the entire team
• Work with the team to constantly evolve our ways of working
• Be an active part of our Engineering community to make sure the discipline keeps advancing throughout the company
• Stay up‑to‑date with industry trends. Learn new tech and non‑tech related skills to grow yourself and your team

• At least 2‑3 years of experience developing Java/Spring Boot based backend services
• Hands‑on experience with Spring Boot and the broader Spring ecosystem
• Experience with MySQL or other relational databases
• Experience with AWS and cloud‑native development
• Experience with version control systems such as Git
• Experience with containerization technologies (e.g., Docker, Kubernetes)
• Experience with distributed message brokers (e.g., Kafka, Kinesis/Firehose)
• Knowledge of monitoring and observability tools like Grafana or Datadog
• Familiarity with continuous integration and deployment (CI/CD) tools such as Jenkins or Git Hub Actions
• Understanding of APIs, microservices architecture, and server‑side processes
• Excellent soft skills: strong communication in English and a high degree of ownership
• True team player with an excellent collaborative mindset and a drive to face challenges and learn

• Familiarity with No
  
  SQL databases (e.g. Mongo
  
  DB).
• Experience with Elasticsearch.
• Understanding of performance optimization and scalability best practices in distributed systems.
• Prior experience in e‑commerce, marketplace platforms, or large‑scale consumer applications.
• Familiarity with event‑driven architectures or domain‑driven design principles.
• Familiarity with machine learning or data engineering is a plus