Senior Backend Engineer (f/m/x)

About CarOnSale

CarOnSale is the AI-powered operating system for B2B used car trading in Europe. Over 40,000 buyers from more than 20 countries trade on the platform, with 85% of inventory exclusive to it, connecting software, pricing intelligence, logistics and financing in one layer.

What You Own

• Own backend development end to end: technology selection, architecture design, and implementation of features that carry platform performance and scale.
• Build AI-first — coding agents, LLMs and AI-assisted development are part of the daily workflow.
• Set the standards: code quality benchmarks, development practices, and CI/CD pipelines.
• Mentor the engineers around you and raise the bar on backend practice.

What You Bring

• 8+ years in software engineering, 5+ focused on backend.
• Deep TypeScript proficiency, with strong Node.js, NestJS and PostgreSQL experience.
• Proven mentorship track record.
• Solid command of Git, Docker and CI/CD pipelines.
• Comfortable in Scrum or Kanban, working with JIRA and Confluence.
• English at C1 level or above.

Nice to Have

WebSockets or other real-time systems, search frameworks such as Elasticsearch or Lucene, automotive or B2B trading background, conversational German.

What You Get

Architecture ownership from day one, 28 days annual leave, company pension with 20% employer contribution, subsidised Deutschlandticket, and FitX or Urban Sports Club membership subsidy.