The quality of your tools and your ability to continue to evolve them will allow you to suppress the need to hire for operational roles, allowing each front-line individual to do more, which simultaneously improving overall coordination (fewer people means coordination is easier) and keeps costs down. Today, the results of Facebook’s engineering leverage ratio means that there is one engineer for every 1.2 million users and despite our blistering user growth, the ratio is growing.

Emphasis mine. (source)