Is 40 too young for a scientist to describe themselves as mid-career? If the term can’t be defined by age, does it refer to landing tenure, to achieving a level of autonomy or to serving on multiple academic committees?Working scientists who no longer define themselves as ‘early career’ tell Julie Gould what this often-neglected career stage means to them in the absence of an agreed definition from funding agencies and scientific governing bodies.This is the first episode in Muddle of the Middle, a six-part Working Scientist podcast series about the mid-career stage in science. Hosted on Acast. See acast.com/privacy for more information.