Space Exporation Technologies Corp., known by most as SpaceX ($SPACEX), known by others as Elon Musk's let's-go-to-Mars company, has made its way through many periods of growth. At one point in 2001 SpaceX was just a pipe dream for Musk, who originally thought he could buy cheap rockets from Russia in order to land a greenhouse on Mars and grow plants.

But when that plan failed, he decided to build his own rockets, and he launched SpaceX. When SpaceX first opened in El Segundo, 160 employees called the company their home. By 2017, 6,000 people were employed by SpaceX in one way or another.

This rapid growth has come with major shifts in company focus, from basic rocket tests, to satellite constelllation development and deployment, to government contracts, to private launches, to more testing, and now to manned flights.

One way to understand SpaceX's brief-but-complex history is by looking at the kinds of people it has been hiring over time. We looked at hundreds of thousands of job listings since 2016, sorted by category (SpaceX's categories, not ours) to tell this story.

Press the "Play" button at the bottom left of the above bar chart. Go ahead, we'll wait.

In short, what we see is ia company that, since 2016, evolved over time from a research and development company into manufacturing, then into a phase in which satellite development took center stage as the company looked to create a sustainable (and revenue-generating) business. Then, from 2018 to 2019, the company broadened its focus to support new avionics engineering, software development and, yes, a lot of manufacturing.