Google’s vice president of finance, has joined Postmates’ board of directors, the latest sign that the on-demand food delivery startup is prepping to take the company public. Postmates announced Friday that Kristin Reinke, vice president of Finance at Google, will join the San Francisco startup as an independent director. Reinke has been with Google since 2005. Prior to Google, Reinke was at Oracle for eight years. Reinke also serves on the Federal Reserve Bank of San Francisco’s Economic Advisory Council. Her skill set will come in handy as Postmates creeps towards an IPO. Earlier this year, the company lined up a $100 million pre-IPO financing that valued the business at $1.85 billion. Postmates is backed by Tiger Global, BlackRock, Spark Capital, Uncork Capital, Founders Fund, Slow Ventures and others. Spark Capital’s Nabeel Hyatt tweeted the news earlier Friday. Happy to welcome Kristin to the board of @Postmates . Great times ahead. https://t.co/nEqu3A2YkE — Nab...