In this article in Thrive Global, my co-author Jay Rosenzweig and I discuss an aspect of diversity that is often overlooked. The most under-represented CxO position for women is the role of CTO. We discuss the root causes as well as initiatives to help increase the number of women in tech and technological leadership: CTOs like Gerri Martin-Flickinger (Starbucks), Nancy Quan (Coca-Cola), Padmasree Warrior (formerly at Cisco and Motorola) and Lisa Schlosser (Thomson Reuters FindLaw).