Since 1975 Horst has been a senior research scientist with the Technische Universität Berlin. His research interests are information retrieval systems, software engineering, software metrics, and the measurement of the quality of software during the software life-cycle.
Now, his research interests are validation of software measures, prediction models, and standardizing measurement principles. From August 1994 to December 1994 he was invited as a researcher by the Gesellschaft für Mathematik und Datenverarbeitung (GMD) in St. Augustin in Germany. In 1998 the book: Horst Zuse: A Framework for Software Measurement (DeGruyter Publisher) was published. From February to May 1998 he was a Visiting Professor with the University of Southwest Louisiana in Lafayette / Louisiana / USA. On December 9, 1998 he received the habilitation (Privatdozent) in the area of Praktische Informatik (Practical Computer Science) by the department of computer science at the Technische Universität Berlin.