How Scout24 is building the next generation of real-estate search with AI

Scout24 operates Germany’s largest real-estate platform, connecting seekers, homeowners, landlords and agents in one ecosystem. AI has supported areas like fraud detection, marketing efficiency, and property valuation for years, and  the rise of powerful large language models created an opportunity to build something new for customers: an intelligent, conversational real-estate assistant.

We sat down with Gertrud Kolb, Chief Technology Officer at Scout24, to hear how her team built a GPT‑5 powered search experience, what they learned about “intelligent interaction,” and how they balanced innovation with quality and trust before launch.

“Be curious, be open, start doing things. Talk with each other, learn from each other—and have fun.”

—Gertrud Kolb, Chief Technology Officer, Scout24

Results at a glance

• GPT‑5 powering Scout24’s conversational search assistant HeyImmo

• Adaptive answer formats: concise summaries, bullet points, or direct listings with image previews

• Custom eval system built on the OpenAI Evals framework to define and measure answer quality

• Company-wide “swarm testing” to refine expectations and stress-test edge cases

• Architecture built for speed and reliability, and rapid improvements

• Tight collaboration with OpenAI Solutions Architects to improve safety, quality, and user experience

Inside the rollout

Scout24’s first priority was search—the core function of its platform. But as the team began prototyping with OpenAI they realised that customers wanted more than improved results. They wanted guidance. “We saw very quickly it’s not only about search. We needed a real-estate expert assistant—a sparring partner—which guides you through the whole platform experience” said Gertrud.

Throughout development, Scout24 worked closely with the OpenAI team. Gertrud described the collaboration as “immensely helpful” in raising answer quality, shaping response structures, and aligning on what ‘good’ looks like for an AI-powered search experience.