Barry O’Reilly is the author of the Leanpub book Residues: Time, Change, and Uncertainty in Software Architecture. In this interview, Leanpub co-founder Len Epp talks with Barry about his background and career, Complexity Science and its connection to his fascinating concept of Residuality theory in the fields Software Architecture and Computer Science, and his experience as a writer. This interview was recorded on April 9, 2024. The full audio for the interview is here: https://s3.amazonaws.com/leanpub_podcasts/FM290-Barry-O’Reilly-2024-04-09.mp3. The Frontmatter podcast is available on our YouTube channel at https://www.youtube.com/leanpub, in Apple Podcasts here https://podcasts.apple.com/ca/podcast/frontmatter/id517117137, and almost everywhere else people listen to podcasts. This interview has been edited for conciseness and clarity.