Materialize is a streaming database that turns SQL queries into real-time materialized views. A materialized view is a pre-computed query result stored in a table. Traditional approach: compute view nightly via batch. Materialize: compute view continuously as data streams in. Every second, Materialize updates the view with the latest data. Analysts query the view and always see current results. Behind the scenes: Materialize watches source systems (Kafka topics, PostgreSQL tables, S3 files) for changes. When new data arrives, it incrementally updates views depending on that data. Updates propagate in milliseconds.