The student teaching experience is one of the most impactful and formative experiences of any preservice teachers' career. Student teaching provides preservice teachers with the professional knowledge and skills needed to be successful teachers through concrete experiences, which formalize professional behaviors. This longitudinal linear mixed model study aimed to examine the change of preservice teachers' performance over time during the student teaching experience. Preservice teacher performance was measured with a modified instrument, and instrument reliability was tested and confirmed as part of this study. As such, it was found that a positive and significant linear trend over the 14-week placement existed and a clear pattern of growth among preservice teachers in the constructs of instructional design, instructional practice, student-centered teaching, teacher professionalism, and reflective and autonomous practitioner. It is evident that the student teaching experience is a valuable macro-level experience that provides a plethora of beneficial micro-level experiences. It is recommended that teacher educators continue to provide preservice teachers with the opportunity to participate in the immersive student teacher experience for a prolonged period. Recommendations for conducting evaluations and delivering feedback to student teachers were also made. As demonstrated in this study, time spent in the student teaching experience is a key attribute to preservice teachers' growth and development as professional educators.