This study's goal was to investigate the effect of homogeneous and heterogeneous pairs in terms of individual differences on group compatibility, flow, and coding performance in pair programming. In line with this goal, five individual difference variables of gender, learning style, friendship, the conscientiousness component of personality traits, and prior knowledge of coding were determined in order to use them in the determination of pairs in pair programming. In the quantitative section of this mixed study, a non-equivalent control group posttest only experimental design was utilized. Sixty-four volunteer university students were included in the study. As a result of the study, it was determined that the homogeneous group experienced a higher level of flow in the case of learning style. On the other hand, in the case of friendship, the homogeneous group experienced a higher level of flow, while the heterogeneous group demonstrated a higher level of coding performance. Concerning the conscientiousness component of personality traits, the heterogeneous group showed a higher level of coding performance. In line with these findings, suggestions for both researchers and practitioners of coding education were made in the full text.