The document discusses Autoscout24's transition from a monolithic architecture hosted on-premises to a microservices architecture hosted on AWS cloud infrastructure. It describes Autoscout24's business of listing over 2 million vehicles and receiving over 3 billion page impressions per month. It outlines the challenges of continuously delivering new features while the system was still running, and how moving to AWS and adopting microservices and DevOps practices helped Autoscout24 rebuild their systems and accelerate development cycles.