MongoDB takes its name from "humongous," and it began as a side part of a bigger plan. Three veterans of DoubleClick, the ad company, set out in 2007 to build a full cloud platform. The database inside it turned out to be the product. Developers liked storing flexible documents instead of rigid tables. By the time MongoDB went public in October 2017, its free version had spread to millions of downloads.

The Part That Won

Dwight Merriman, Eliot Horowitz, and Kevin Ryan founded the company as 10gen in New York in 2007. They first tried to build a platform where developers could run whole apps. About a year in, Google launched App Engine, and the plan looked crowded. The team dropped the platform and kept the database. It released MongoDB as open source in February 2009. In 2013 the company took the database's name.

Ten Years to the Day

MongoDB priced its offering at $24 a share on October 18, 2017, above its planned range. The stock opened at $33 and closed its first day on Nasdaq at $32.07, up about 34 percent. It sold 8 million shares and raised $192 million before the underwriters' extra shares. The IPO landed close to the company's tenth birthday. Its cloud service, Atlas, then grew into its largest business. MongoDB still trades on Nasdaq as MDB.

Cover: The Fall of the Giants, Salvator Rosa. Art Institute of Chicago, public domain. Chosen for the fall of the giants (humongous).