Senior Software Engineer – Backend (AI)

Requirements

• Strong experience as a backend engineer in production environments
• Solid skills in Kotlin, Java, or a similar JVM language, and comfort picking up a new stack
• Experience designing and scaling APIs and distributed systems where reliability and correctness matter
• Comfort building from scratch rather than extending established platforms and internal tooling
• A strong sense of ownership, and the ability to move things forward without a lot of scaffolding around you
• Clear communication, particularly across engineering disciplines

Nice to Have

• Experience working alongside machine learning or data engineering teams
• Exposure to LLM-based systems, RAG, or agent architectures
• Experience with AWS, and with Bedrock or a comparable model platform
• Interest in AI-assisted development workflows

What You'll Be Doing

• Design and build the backend services and APIs that power Personio's AI Assistant and agent experiences
• Build out the underlying platform that upcoming agentic products across Personio will be built on
• Own features end to end, from problem definition through to production
• Work directly with machine learning engineers on the systems around retrieval, prompting, and model interaction
• Make architectural decisions in a young, fast-moving domain where the patterns are still being set
• Collaborate with Product, Design, and the teams building AI features into their own product areas

Perks and Benefits

• Competitive salary and equity
• 28 days holiday, increasing with tenure
• Hybrid working model (2 days per week in the office)
• 20 Flex Days to work from anywhere in Europe
• A strong engineering culture focused on ownership and impact