By at least one measure, Lyft is very big.
At the end of 2018, the ride-hailing company had 4,680 full-time employees, triple the total at the end of 2016, according to Lyft's IPO prospectus filed on Friday.
That's more employees than Facebook, Google or Dropbox had when they filed for their public market debuts. The rapid expansion points to the growth of technology-enabled transit, and Lyft's need to aggressively hire in an effort to keep pace with larger rival Uber, which said in October it had more than 20,000 employees.
Across Lyft's more than 50 offices and its "driver hub" service centers, there were a total of 4,791 employees at the end of 2018. The company also pays contractors and consultants, while drivers are considered independent contractors.
Dropbox employed 1,858 people at the time of its filing last year. Facebook had 3,200 people when it field to go public in 2012, and Google had 1,907 at the time of its 2004 prospects.
Around 36 percent of Lyft's employees focus on design, engineering and product management. Nearly 300 people worked on its trust and safety team, handling especially sensitive issues, and Lyft said there were "several hundred" people located at its Level 5 Engineering Center in Palo Alto, California, where the company works on self-driving car technology development.
Lyft said none of its employees are unionized, and the company has "not experienced any work stoppages."
In the same period that headcount tripled, Lyft said that the number of active riders increased by more than that amount.