Prompt optimization has become crucial for enhancing the performance of large language models (LLMs) across a broad range of tasks. Although many research papers demonstrate its effectiveness, practical adoption is hindered because existing implementations are often tied to unmaintained, isolated research codebases or require invasive integration into application frameworks. To address this, we introduce promptolution, a unified, modular open-source framework that provides all components required for prompt optimization within a single extensible system for both practitioners and researchers. It integrates multiple contemporary discrete prompt optimizers, supports systematic and reproducible benchmarking, and returns framework-agnostic prompt strings, enabling seamless integration into existing LLM pipelines while remaining agnostic to the underlying model implementation.

Large language models suffer from positional biases like the "Lost in the Middle" (LiM) phenomenon and recency bias, which reduce the effective utilization of long contexts. In this work, we investigate the role of Positional Encodings in this context. Our empirical study confirms the persistence of these biases in modern large language models. Drawing on these findings, we introduce Caliope, a training-free framework for calibrating Positional Encodings at inference time. Our calibrators yield substantial improvements on needle-in-a-haystack and cross-chunk reasoning benchmarks, and offer a practical, lightweight method for improving long-context utilization.