Purpose: The purpose of this paper is to reflect on carers’ experiences of being involved in the development of a web-based support programme for carers of people with heart failure (CPwHF), and discuss the challenges related to their involvement in the development process. The focus was on the different phases in the project as well as the methodological challenges and opportunities that occurred in the user group sessions conducted. Design/methodology/approach: This research adopt an explorative design studying a co-design process to develop an information and communication technology based support programme for and with CPwHF. Habermas’ concepts of lifeworld and system are used as a theoretical framework to analyse the co-design process employed in the study. Findings: Reflecting on the co-design approach adopted, the findings highlight the methodological challenges that arise with carer involvement and the possible tensions that occur between researchers’ ambitions to include users in the design process, and the goal of developing a product or service, in the different phases of the design process. Originality/value: Findings highlight that there is a tension between the system and lifeworld in the co-design process which are not totally compatible. The paper highlights that there is a need to develop flexible and reflexive human-centred design methodologies, able to meet carers’ needs and ideas, and at the same time balance this with proposed research outcomes.