What has happened since the last time we saw each other?': methodological challenges in an unplanned longitudinal qualitative investigation into binational couples in Spain

Based on the experience derived from a 12-year research process (2006-2018) on mixed couples undertaken by a team of social researchers and financed by the Spanish Science, Technology and Innovation System, we discuss how our practice and our process of constructing results reinforce, but also qualify and modify, some aspects of classical ethnographic theory and Qualitative Longitudinal Research. Given the difficulties of securing funding for long-term projects in a context of short-term contract funding, and the importance of longitudinal methodology for understanding phenomena associated with migrant populations, we had no choice but to resort to the 'ethnographical imagination'. In doing so, the fundamental question we address is: how can a longitudinal study be carried out on the basis of projects that were not originally designed with that end in mind and within the framework of a research environment determined by the standardised guidelines of a National Research Plan?