The latter refers to any tool that uses the generated features to rescore PSMs. These abstractions allow for a more transparent rescoring workflow and facilitate the future addition of new feature generators or rescoring engines. Using an abstract base class as template for feature generators, we ensure that any newly added feature generator provides the required functionality within the unified API, streamlining new integrations. To avoid unnecessary file reading and writing, all feature generators and rescoring engines receive and update the in-memory psm_utils.PSMList object. This significantly reduces runtimes compared to the previous MS Rescore version, which heavily relied on intermediary on-disk files.