Pushy is Netflix's WebSocket server maintaining persistent connections with devices running the Netflix app. It evolved from a message delivery service to an integral part of the Netflix ecosystem. Pushy handles hundreds of millions of concurrent WebSocket connections, delivering hundreds of thousands of messages per second, with a 99.999% message delivery reliability rate. Initially developed for FireTVs, Pushy's reach has expanded to nearly a billion devices, including mobile devices and older devices with limited capabilities. To handle this growth, Pushy has undergone several improvements, including rewriting the message processor using Netflix paved-path components, migrating the Push Registry to KeyValue for better performance and scalability, and implementing exponential scaling policies based on the number of connections. These enhancements have made Pushy more reliable, stable, and efficient, enabling it to support the growing number of devices and meet the demands of new features.