Philippe Kruchten is a professor of software engineering at the University of British Columbia in Vancouver, Canada. He joined academia in 2004, after a 30+-year career in industry, where he worked mostly with large software-intensive systems design in the domains of telecommunication, defense, aerospace, and transportation. Some of his experience in software development is embodied in the Rational Unified Process (RUP), whose development he directed from 1995 until 2003. He's the author or co-author of Rational Unified Process: An Introduction (Addison-Wesley, 1998), RUP Made Easy: A Practitioner's Guide (Addison-Wesley, 2003), and Software Engineering with UPEDU (Addison-Wesley, 2003), as well as earlier books about programming in Pascal and Ada. He received a doctoral degree in information systems (1986) and a mechanical engineering degree (1975) from French engineering schools. Robert Nord is a principal researcher at the Carnegie Mellon University Software Engineering Institute, where he works to develop and communicate effective methods and practices for agile at scale, software architecture, and managing technical debt. He is coauthor of the practitioner-oriented books Applied Software Architecture (Addison-Wesley, 2000) and Documenting Software Architectures: Views and Beyond (Addison-Wesley, 2011) and lectures on architecture-centric approaches. He received a PhD in computer science from Carnegie Mellon University and is a distinguished member of the ACM. Ipek Ozkaya is a principal researcher at the Carnegie Mellon University Software Engineering Institute. Her primary work includes developing techniques for improving software development efficiency and system evolution, with an emphasis on software architecture practices, software economics, agile development, and managing technical debt in complex, large-scale software-intensive systems. In addition, as part of her responsibilities, she works with government and industry organizations to improve their software architecture practices. She received a PhD in Computational Design from Carnegie Mellon University. Ozkaya is a senior member of IEEE and the 2019-2021 editor-in-chief of IEEE Software magazine.