Batching GEPA's reflective proposals cut wall-clock time in half and still improved held-out scores, from 68.9 to 72.1 percent on LiveBench-Math
AspireAI community · arXiv (GEPA authors)
*Reflective prompt optimization improves agents, but the optimization loop itself is a resource-hungry workload whose sequential structure leaves parallel capacity idle.* The authors extend the open-source GEPA optimizer to propose and evaluate a batch of candidates per optimization step instead of one. In a sweep over two tasks, most batched runs finished in half the wall-clock time or less, and the fastest in about a quarter to a third. Batched settings also scored higher on held-out test sets: 68.9 to 72.1 percent on LiveBench-Math with a 2x2 configuration, and 49.0 to 60.0 percent on HoVer with 8x1. A simple runtime model explains the measured speedups under a finite worker pool, and batched settings spend their metric-call and dollar budgets more efficiently.
The honest caveat is the scope: the sweep covers two tasks, and this is a workshop paper, so the parallel-proposal axis is a first look rather than a settled recipe. The widening insight is that a reflective optimization step has several axes to scale along, and this work only begins to price them.
Read the story and explore more from the AspireAI community.
Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.