What is a real-time database? (and why your startup probably needs one)

A real-time database keeps an application synchronized with live data by pushing updates instantly, eliminating the need for traditional polling. It uses persistent connections like WebSockets and an event-driven, publish-subscribe model where clients subscribe to specific data queries. When underlying data changes, the backend automatically re-executes the relevant queries and pushes the new results to subscribed clients. This architecture reduces backend complexity and network load, making it ideal for building collaborative SaaS tools, e-commerce platforms, and other applications requiring a responsive user experience.