Abstract
To advance knowledge about evolution of practices within a software organisation, we offer a retrospective reflection based on several years of research into a software unit at Ericsson AB. Covering 16 years of evolution, we developed multiple publications from continuously expanding sources of software technology implementation data. While these publications report from specific junctures of software practice evolution at the unit, our retrospective reflection allows us to consider the impacts of the unit’s investments into two technology paradigms over the sixteen-year period: first into CMM-RUP with a focus on discipline and structured practices and years later into Agile-Lean with a focus on flexibility and responsive practices. Hence, we adopt retrospective reflection to investigate how imprints from the two paradigms, despite considerable timespan between the related technology implementations, eventually complemented each other in the unit’s software practices. Because one paradigm focuses on discipline and structured practices and the other on flexibility and responsive practices, our retrospective reflections consider how the two paradigms together impacted the software unit’s ambidextrous capability. As a result, we advance the idea that as software organisations over time invest in complementary technology paradigms they leave important technology traces with sustainable impacts on their software practices.