AI Test Engineer (m/f/d) at SIXT

As a Customer Service Agentic AI QA Engineer (m/f/d), you ensure that SIXT’s virtual agents and Generative-AI–powered workflows deliver reliable, safe, and delightful support across all customer service channels. You design and run intelligent test strategies for LLM- and agent-based systems, combining classic QA skills with a deep understanding of agentic automation, conversational AI, and customer service KPIs. YOUR ROLE AT SIXT • Design and execute end-to-end test plans for customer service virtual agents (voice, chat, email). Build and maintain agentic AI test suites validating autonomous workflows (e.g., booking changes, billing, damages). • Define and monitor AI quality metrics such as resolution rate, deflection, CSAT, and safety violations. Develop test data and synthetic scenarios for edge cases, ambiguous queries, and multilingual requests. • Evaluate agent behavior through reasoning traces, tool-use decisions, and memory usage. • Implement and improve automated testing frameworks for conversational flows, APIs, and integrations. Contribute to LLMOps / CI/CD pipelines to automatically detect regressions. • Perform bias, fairness, and safety testing in line with SIXT policies and regulatory expectations. Collaborate with cross-functional teams to refine requirements and acceptance criteria. • Document defects, test results, and insights clearly for stakeholders.YOUR SKILLS MATTER • Foundations 2/ 3 years of experience in software QA / test engineering. Strong understanding of testing principles: functional, regression, integration, performance. • AI Testing Hands-on experience testing AI or ML systems such as LLM chatbots or recommendation engines. Familiarity with key concepts of multi-agentic systems, agentic frameworks (e.g., LangChain), AWS AgentCore. • Automation Scripting skills in Python and experience with REST API testing. • LLMOps: Understanding of LLMOps / MLOps: versioning, monitoring, rollback strategies. • Customer Focus Experience or interest in customer service processes and KPIs. • Communication Excellent analytical, documentation, and communication skills. Fluency in English; German or additional languages a plus.WHAT WE OFFER • Generous Time Off Enjoy 28 days of vacation, an additional day off for your birthday, and 1 volunteer day per year • Work-Life Balance & Flexibility Benefit from a hybrid working model, flexible working hours, and no dress code • Great Employee Benefits Access discounts on SIXT rent, share, ride, and SIXT+, along with partner discounts • Training & Development Participate in training programs, external conferences, and internal dev & tech talks designed for your personal growth and development • Health & Well-being Private health insurance to support your well-being • Additional Perks Enjoy the Coverflex advantage system to enhance your employee experience