This work in progress paper presents the design of a study developed to identify the influence of engineering students' extracurricular involvement on their career aspirations and professional development. This study investigates how students' extracurricular involvement influences their career certainty and confidence in job preparation, with emphasis on examining the types of involvement and specific aspects of involvement that lead to these outcomes. The study will be conducted longitudinally over three years with undergraduate engineering students at a single institution to examine the influence of extracurricular involvement over time and the pathways students pursue through undergraduate engineering in relation to their career goals. Research findings extend the literature by providing a longitudinal examination of how students' involvement and career aspirations evolve over their undergraduate years, providing opportunities to identify mechanisms of influence and potential causal effects. This research extends the literature by connecting student organization involvement to career aspirations and preparation, offering university stakeholders information to develop interventions to help students in their transition to the workforce.