This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. Part four of the book proposes that Barad’s feminist ‘new materialism’ provides a key to understand and act upon the relational co-production of technology and ageing. It focuses on one issue: ageing-in-place policy and how it technologically articulates ‘home’. The book then focuses on then practices of design, as forms of intervention. It also examines how social research methods might open up or close down the sociotechnical imagination. Shifting the focus from designers, engineers and policymakers, the authors proposes that social science practices themselves partake in the making of the relationship between ageing and technology. The book also focuses on the work of Mol and Law to trace how realities of ageing and technology are enacted, emphasising the plural, and multiple character of such enactment. Comfort’s insight into how technological imaginaries are linked to health measurement infrastructures and conventions is valuable.