A few months ago, Amplitude, a San Francisco-based company that helps companies build better products through advanced analytics, made the cut for Forbes' 2018 list of Next Billion-Dollar Startups. Now it's one step closer: The startup raised $80 million in a new round of venture funding led by Sequoia Capital at a valuation of $850 million.With the new funding, Spenser Skates, the company's 30-year-old CEO and an alumnus of the Forbes 30 Under 30 list, plans to expand internationally, with new offices in the works in London, Paris and Singapore, and to continue to add functionality to its software. "Our goal is to be what Salesforce was for sales and Adobe was for marketing for the product world," he said. Pat Grady, the Sequoia partner who led the investment, said that he had been tracking Skates and his cofounders for several years. "A couple of portfolio companies have whispered in our ear, 'Hey this is a really cool product,'" he said. "There are a lot of tools that do similar things. The reason that we've invested in Amplitude now is that it's starting to become abundantly clear that they're risen above that pack." The theory underlying the investment, he said, is similar to that for Sequoia's earlier investments in customer-experience software companies Qualtrics, which recently agreed to be acquired by SAP for $8 billion, and Medallia, which is expected to go public in 2019.