Track reconstruction in high-multiplicity environments with the ATLAS Detector at the LHC

During 2017, the Large Hadron Collider provided record-breaking integrated and instantaneous luminosities, resulting in huge amounts of data with the number of interactions per bunch crossing being significantly beyond design values. I discuss the track reconstruction performance with the ATLAS detector in high-multiplicity data. I also discuss the expected tracking performance in even higher multiplicity environments in future data-taking at the high-luminosity LHC.