While STEM careers emphasize job ability and have become more prestigious in today's economy, there is still a wagedisparity between men and women in STEM. This research examines the pay records of 62,000 individuals in STEMfields via a website that shares verified wage information, levels.fyi. Using stepwise regression analyses that simulate alifetime job trajectory, we find factors driving the gender wage difference for software engineers and data scientists. Theexpected base and compensation wage gaps demonstrate that the current gender pay gap is largely explained by fewerwomen taking top-level positions with a long career path. Among job titles, we found newly created positions like datascientist to show less apparent gaps. Our findings suggest that promoting women to higher positions and longer careersin the IT industry will help to reduce the pay gap, ultimately contributing to a larger pool of advanced workforce.