GitHub's employee resource group for marginalized genders, the Adacats, initiated a mentorship program to address career advancement challenges faced by its members, launching a pilot in July 2019 with 10 mentor-mentee pairs in the engineering department. The program aimed to facilitate career growth in GitHub's dynamic environment, receiving feedback that highlighted the need for more structured guidance and better communication between managers, mentors, and mentees. In response, the program was renamed the Adacats Mentorship Program and expanded to include detailed documentation, growth plans, and structured manager interactions, emphasizing overall growth rather than just promotions. The initiative, which rolled out company-wide in May 2020, underscored the importance of iterative learning, manager involvement, and sponsorship training to better support marginalized groups. Despite initial challenges, the program was positively received, leading to promotions, team transitions, skill development, and increased participation, demonstrating the effectiveness of mentorship in fostering career growth.