The HPI is a big family. Besides 14 professors and over 200 senior researchers, senior researcher, lecturers and staff, HPI has around 550 students. Over the past 20 years, HPI has bid farewell to many graduates, and, at the same time, welcomed new employees to the institute. Many individuals have played an integral role in defining HPI, as we live through our students, faculty, researchers and staff. On our 20th birthday, we will hear from some of them.