Imposter Phenomenon (IP), described as the persistent feeling of intellectual fraudulence despite evidence of competence, affects many computing students and has been linked to diminished academic engagement, and social withdrawal. While prior research has established IP’s prevalence and contributing factors in computing education, little is known about how it manifests in computing students’ daily academic lives. This paper presents findings from a seven-day Ecological Momentary Assessment (EMA) study in which 34 computing students submitted three daily reports capturing their experiences related to the Imposter Phenomenon (IP). Participants reported on stress levels, context (people, location, thoughts, tasks, and feedback), and six IP characteristics(feelings of over-preparation, feelings of procrastination, feeling a need to be the best, fear of being shamed/humiliated because of performance, feeling incapable/incompetent and a fear of success leading to higher expectations) in context. Our analysis reveals patterns between feedback type, daily stress, and the emergence of IP characteristics, offering insight into how everyday interactions may reinforce or relieve imposter feelings. By linking momentary experiences with psychological outcomes, we contribute empirical evidence for the design of intervention(s) aimed at improving student well-being in computing education. This is the first known EMA study to examine IP in computing students’ daily context.