Stream stitching is a technique that is used in the ad tech industry to improve the efficiency and effectiveness of video advertising. It involves combining multiple video streams, or "stitching" them together, in order to create a single, seamless stream of content that can be delivered to the viewer. This can be useful in situations where an advertiser wants to target a specific audience with a personalized ad, but the content that the audience is watching is being delivered from multiple sources. By using stream stitching, the advertiser can combine the relevant video streams into a single stream, and then insert their personalized ad into that stream at the appropriate time. This allows the ad to be delivered to the right audience, in the right context, and in a way that is less disruptive to the viewer's experience. Stream stitching is often used in conjunction with other ad tech tools, such as demand-side platforms (DSPs) and data management platforms (DMPs), to help improve the targeting and personalization of video advertising.