In this talk we'll dive into the infrastructure that seedtag has built for it's online advertising product. Developed as a microservices-based architecture on top of Kubernetes, we handle billions of pageviews every month in a globally distributed platform that has to respond with tight milliseconds requirements. We'll go into the mix of technologies that we are using (Kafka, Mongo, Spark, Druid, ...) and some of the challenges that we have faced with them.