The creation of Intreo as a one-stop shop for jobseekers in Ireland occurred during the financial and sovereign debt crisis period of 2010–16. The organisational merger was the product of an extensive programme of successful administrative reorganisation and service integration that deserves attention. This article begins with an overview of the policy to merge insurance-based unemployment benefit, discretionary social welfare payments and labour market activation measures, as well as the various political and institutional rationales that led to this development. Drawing on the special issue framework concerning how the interaction of ideology, institutions and interests comes into play during policy change, we consider the contextual factors that facilitated the rapid implementation of the programme and its overall successful execution. Whilst focusing on the success, we also critically point out the inhibitors in the implementation chain, some of which predated the crisis, as well as problems during the implementation process, such as delays in the national rollout and back-office supports. We identify the main contributing factors for successful implementation of a one-stop shop for activation and unemployment services as (a) a high problem pressure, (b) a small and agile implementation team, (c) changing labour relations (e.g. binding arbitration, weakened unions) and (d) a modern communication strategy.