HybridFlow: Adaptive Task Scheduling for Fast and Token-Efficient LLM Inference in Edge-Cloud Collaboration

Large language models (LLMs) exhibit impressive reasoning and problem-solving abilities, yet their substantial inference latency and token consumption pose major challenges for real-time deployment on resource-limited edge devices. Recent efforts toward edge-cloud collaboration have attempted to mitigate this issue, but most existing methods adopt coarse-grained task allocation strategies-assigning entire queries either to the edge or the cloud. Such rigid partitioning fails to exploit fine-grained reasoning parallelism and often leads to redundant computation and inefficient resource utilization. To this end, we propose HybridFlow, a resource-adaptive inference framework that enables fast and token-efficient collaborative reasoning between edge and cloud LLMs. HybridFlow operates in two stages: (1) task decomposition and parallel execution, which dynamically splits a complex query into interdependent subtasks that can execute as soon as their dependencies are resolved; and (2) resource-aware subtask routing, where a learned router adaptively assigns each subtask to the edge or cloud model according to predicted utility gains and real-time budget states. Comprehensive evaluations on GPQA, MMLU-Pro, AIME, and LiveBench-Reasoning demonstrate that HybridFlow effectively reduces end-to-end inference time and overall token usage while maintaining competitive accuracy.