2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/227199This article describes the design, testing and production of the ATLAS Region of Interest Builder (RoIB). This device acts as an interface between the Level 1 trigger and the high level trigger (HLT) farm for the ATLAS LHC detector. It distributes all of the level 1 data for a subset of events to a small number of (16 or less) individual commodity processors. These processors in turn provide this information to the HLT. This allows the HLT to use the level 1 information to narrow data requests to areas of the detector where level 1 has identified interesting objects.13 pages, 7 figuresInstrumentation and DetectorsThe ATLAS High Level Trigger Region of Interest Buildertext