Sarah Smith, a former executive at Facebook and Quora, has joined investment firm Bain Capital Ventures as its first female partner. She will be based in San Francisco and will focus on early-stage investments across business and consumer technologies and marketplaces. Most recently, Smith was as an investor at Graph Ventures, where she funded more than 20 seed and Series A investments, including BetterUp, Winnie, Motion, OhmniLabs, Heartbeat, Strive, and Twine.