PushOwl, a B2B SaaS solution for e-commerce marketing, faced challenges in efficiently managing and retrieving data related to web push notifications, which are critical for their campaign reporting system used by over 22,000 businesses. Initially, PushOwl relied on a PostgreSQL database to store push notifications and generate campaign reports, but as data volume increased, this approach resulted in slow query performance and user experience issues. To address these problems, PushOwl transitioned to an event streaming solution using Apache Kafka and ksqlDB, which allowed for more efficient data handling and scalable stream aggregation. By integrating ksqlDB into their tech stack, PushOwl could leverage Kafka's event streaming capabilities to manage high data throughput and ensure timely updates to their PostgreSQL database. The solution also involved using Kafka Connect to store aggregated event data in cloud storage for further analysis and debugging, ultimately enhancing the performance and scalability of PushOwl's marketing dashboard.