A content delivery node receives data packets carrying content from an upstream source of content, and writes segments of the received content directly to a memory buffer of a memory using direct memory access (DMA) data transfers. The node derives, for each segment, respective segment-specific metadata based on contents of the segment, and stores the respective segment-specific metadata in the memory. The node receives from multiple downstream client devices respective requests for the same content. Each request includes client-specific information. Responsive to the requests, the node: identifies one or more segments that satisfy the requests; generates, for each client device, client-specific metadata using the client-specific information and the segment-specific metadata for the one or more segments; constructs, for each client, a client-specific data packet that includes the one or more segments and the client-specific metadata; and transmits the client-specific data packets to the downstream client devices.