Senior Software Engineer (d/f/m) – Internal AI

Personio's intelligent HR platform helps small and medium-sized organizations unlock the power of people by making complicated, time-consuming tasks simple and efficient. Our team of 1,500 Personios is building user-friendly products that delight our 15,000+ customers and their 1.5 million employees. Ready to make an impact from day one?

Senior Software Engineer (d/f/m) – Internal AI

About The Role

We are hiring a Senior Software Engineer to build the internal products and tools Personio runs on, with AI at the centre of what you build.

Personio is on the path to becoming an AI-first company, redesigning how every department operates, and the Internal AI team is leading that transformation from the inside. We work as a product team for Personio's own operations: embedding directly in business functions, building the agents and automations that make change real, and staying accountable for outcomes. At the core of that mission is Personio's internal AI operating system: the layer of agents, automations, and tools each function runs on.

As a Senior Software Engineer on the team, you design, build, and maintain internal products and tools: complex agents, cross-functional automations, and the applications around them. You own software end-to-end, from architecture through to production and ongoing maintenance. The role sits where strong software engineering meets applied AI: you bring the engineering depth to make the hardest problems solvable and the judgment to build the right thing.

This role requires 2 days per week in the office and is based in Munich, Berlin, or Dublin.

Who will thrive here

This is a hands-on engineering role in a team that is still taking shape. Priorities will move as the business changes, and some of the work will be scrappy before it is polished. The people who do best here tend to share these traits:

• Ownership beyond your remit: you spot a problem, propose a fix and ship it end-to-end, without waiting to be asked
• Comfort with ambiguity: you are energised by building new things and by changing direction when the evidence says so, rather than maintaining mature systems on a fixed roadmap
• Pragmatic judgement: you know when to buy, when to build, when an LLM is the right tool, and when deterministic logic or a redesigned process works better
• Real AI in production: you have put AI in front of real users and can talk about the outcome in numbers, such as latency cut, hours saved or adoption
• Clear, structured communication: you can explain a design and your trade-offs in a way that is easy to follow, for engineers and for colleagues outside tech
• A partner to the business: you work closely with the teams you build for, learn their context and stay accountable for the result
• A realistic view of AI: you are curious and use it every day, and you are honest about its limits, costs and failure modes
• A multiplier for others: you document what you build, share what works and help the people around you get better
  
  

If you prefer fixed roadmaps and stable priorities, this may not be the right fit. If you enjoy building the road as you go, we would like to meet you.

## What you'll do

Find the right problems to solve

• Work with business teams to identify where AI and automation can make a real difference, and decide whether an LLM, an automation, or a redesigned process is the right answer
• Start simple, then add structure where it helps, for example deterministic logic alongside LLM steps, based on how the product performs with real users
  
  

Build and ship internal products and tools

• Design, build, and ship Personio's internal products and tools end-to-end: complex agents, cross-functional automations, and the applications and interfaces around them
• Make the architecture calls: choose the right patterns, manage complexity, and make pragmatic trade-offs between reliability, cost, and delivery speed
  
  

Productionise and maintain

• Define what "done" means for an internal AI product: secure auth, error handling, monitoring, rollback, and documentation, then build to that bar
• Own systems over their full lifetime: maintain, monitor quality with Personio's eval platform, catch degradation, and keep them reliable long after launch
  
  

Contribute to the AI platform

• Build on and extend Personio's internal AI platform: agent orchestration, the eval platform, context layer, and connector library
• Feed production experience back into the platform: the use cases you build surface the requirements, and you collaborate with AI Platform engineers to evolve shared infrastructure and the skills library so what you build compounds across the team
  
  

Engineering standards

• Contribute to Personio's internal AI engineering standards: what production-grade solutions look like, how they are evaluated, deployed, and maintained
• Document solutions clearly so they can be maintained, extended, and handed over without you in the room
  
  

## What you need to succeed

• 4+ years building and shipping production software as a software engineer or developer, working independently. This is a software engineering role, not a data science or ML research role
• Strong software engineering skills in at least one modern backend language, across APIs, services, and data integration
• Hands-on experience building production AI products that real users rely on, not only prototypes or personal projects: agentic workflows and RAG pipelines with LLM APIs, agent frameworks (e.g. LangGraph), and MCP
• Judgement about where AI adds value and where it's overkill, including build-versus-buy decisions
• A track record of production-grade work: testing, observability, and secure handling of auth and data
• Experience deploying and running services in the cloud (AWS, Docker, CI/CD)
• Clear, structured communication: you can walk others through an architecture or a trade-off and handle challenge constructively
• AI fluency: hands-on experience using AI to improve your workflow, and the sound judgment to know exactly when to rely on it and when to step in yourself
  
  

Nice to have

• Python, our primary backend language, across APIs, services, and data integration
• TypeScript and React for internal interfaces
• Kotlin
  
  

Not a Python or TypeScript expert yet? If you are a strong engineer in another language and keen to learn, we want to hear from you.

Why Personio?

Personio is an equal opportunities employer, committed to building an integrative culture where everyone feels welcomed and supported. We embrace uniqueness and understand that our diverse, values-driven culture makes us stronger. We are proud to have an inclusive workplace environment that will foster your development no matter your gender, civil status, family status, sexual orientation, religion, age, disability, education level, or race.

Aside from our people, culture, and mission, here are some of the other benefits that make Personio a great place to work:

• A competitive reward package, reevaluated each year, that includes salary, benefits, and pre-IPO equity
• 28 days of paid vacation, plus an additional day after 2 and 4 years
• 1 fully paid Impact Day to make a difference for the environment and society
• Generous family leave, child support, mental health support, and sabbatical opportunities
• An office-led, remote-friendly approach, including opportunities to work from home and international locations. Many teams have designated days for gathering in the office to enhance collaboration and foster a sense of community
• Meals, cultural initiatives, and events like local Summer Sessions and year-end celebrations, plus healthy snacks, drinks, and a weekly catered lunch