Marcel Karnstedt received his Diploma (M.Sc.) from the Martin-Luther-Universität Halle-Wittenberg, Germany, at the end of 2003. From January 2004 to February 2009 he worked as a research associate and teaching assistant with the Databases & Information Systems Group (head: Prof. Dr.-Ing. habil. Kai-Uwe Sattler) at the Ilmenau University of Technology, Germany. That is where he also successfully completed his Ph.D. (summa cum laude).

In March 2009 he moved to the Digital Enterprise Research Institute (DERI), National University of Ireland, Galway (NUIG). He worked with the Unit for Information Mining and Retrieval (UIMR) and started as a Postdoctoral Researcher in the CLIQUE project on analyzing and visualizing large graphs and networks, specifically social networks and biological networks. Since December 2009 he also holds an adjunct lectureship at NUIG. From November 2010 to October 2013 he had been employed as a Senior Postdoc, mainly responsible for DERI's part of the ROBUST project, an EU-funded international project focusing on risks and opportunities in huge-scale business communities. Further, he actively contributed to the tasks of query processing and sensor mining in the SPITFIRE project on combining the "Internet of Things" with the "Web of Things".

From November 2013 to July 2015 he held a permanent position with Bell Labs in Ireland, the research arm of Alcatel-Lucent. He worked with the Scalable Data Processing Activity as a part of the IP Platforms Research Program. His main responsibilities revolved around shaping the research agenda of the team focusing on large-scale data processing and data management for scalable analytics. He further played a key role in a project on next-generation communication. He worked on designing and integrating a novel context engine based on scalable text and graph analytics, as well as implementing core components of the server backend of the project's mobile app.