This document discusses Infobip's journey towards enabling real-time querying of aggregated data. Initially, Infobip had a monolithic architecture with a single database that became a bottleneck. They introduced multiple databases and microservices but querying spanned databases and results had to be joined. A data warehouse (GREEN) provided reporting but was not real-time. To enable real-time queries, Infobip implemented a lambda architecture using Kafka as the real-time data pipeline and Druid for real-time querying and aggregations, achieving sub-second responses and less than 2 seconds of data delay. This allows real-time insights from ingested messaging data while GREEN remains the batch/serving layer.