Systems and methods are described for stateless network function virtualization. Embodiments operate in context of a data network, in which network middleboxes are virtualized, for example, for added scalability and fault tolerance. The virtualized middleboxes can implement state-reliant network functions in a manner that decouples the state from the packet processing pipeline, while maintaining reliability and throughput even at very high data rates. Various embodiments include novel packet processing pipeline architectures, novel thread coordination structures (e.g., including batching and buffer pool sub-structures), novel remote state data store structures, and/or other novel features.