Senior Middleware Engineer (d/f/m)

Job description mobile.de is Germany’s largest vehicle marketplace, with more than 1.6 million listed cars, commercial vehicles, motorcycles, and e-bikes (annual average 2025). Both private customers and registered vehicle dealers use the platform and benefit from more than 140 million visits per month*. As a “one-stop shop,” mobile.de’s offering includes not only buying and selling, but also financing and leasing solutions. Founded in 1996, the company is a subsidiary of Adevinta, a global leader in online classified portals.

Based in Berlin-Charlottenburg, we offer a dynamic environment where growth, learning, and collaboration are at the heart of everything we do. If you are driven by an eagerness to disrupt, have a passion for collaboration, and are excited about shaping the future of mobility, we would love to hear from you.

What You’ll Do & Who You Are As a Senior Middleware Engineer (d/f/m), you’ll build and run the integration layer that connects our systems and enables reliable data and process flows across the company. In this role you provide or connect to several interfaces within the company. Starting from classic ETL batch processing to event based Kafka / SOA web service integration - with a strong focus on stability, maintainability, and pragmatic engineering.

Core stack (today): Talend (ESB runtime), Java, Apache Camel, ActiveMQ, Kafka.

Job requirements Must-have:

• 3+ years of hands-on experience in middleware, ETL and/or interface development and integrations
• Strong practical experience with Java development in agile, cross-functional teams.
• Excellent understanding of HTTP, REST APIs, and JSON; good familiarity with common data formats (e.g., XML/CSV).
• Solid foundation in Linux, databases, and networking fundamentals (cloud exposure such as AWS is a plus, not required).
• A structured problem-solving approach with a focus on root-cause analysis and sustainable fixes.
• Ability to work independently, learn quickly, and communicate clearly with technical and non-technical stakeholders.
• Fluent English.

Nice to have:

• Experience with Apache Camel patterns and integration/service testing approaches.
• Practical experience with CI/CD pipelines (e.g. Github actions).
• Knowledge of integration security, secrets management and data privacy best practices.
• Experience integrating with CRM/ERP systems (e.g., Salesforce, Microsoft Dynamics 365 Business Central).
• German language skills.

Job responsibilities

• Design, build, and operate application integration solutions (ETL + API/messaging) with a focus on reliability, performance, and maintainability in a cloud based runtime environment
• Work with stakeholders, developers, and architects to clarify requirements and translate them into integration designs, mappings, transformations, and error-handling concepts.
• Implement and maintain java-based integration services using visual Talend IDE.
• Build and support messaging/event-driven integrations using ActiveMQ and Kafka (e.g., retries, routing, dead-letter handling, correlation/traceability concepts where applicable).
• Own day-to-day operations during business hours: troubleshooting, incident resolution, patching, and continuous improvements (no on-call duty).
• Plan and execute upgrades, migrations, consolidations, and configuration changes with minimal disruption.
• Maintain strong documentation: architecture notes, runbooks, and change records that enable others to operate and support the platform.
• Continuously improve how we do integrations (standards, templates, automation, observability and quality practices).

Job benefits Working at mobile.de comes with its perks! Enjoy the following benefits (some of many):

• Rewards: competitive base salary and participation in the company’s incentive programs.
• Plan for the Future: On top of the statutory retirement insurance, we offer