Fast Engineering is the second upgrade of the first path for the Monkey Engineer, costing $300 on Easy, $350 on Medium, $380 on Hard, and $430 on Impoppable. This upgrade increased the build speed of sentry guns by 66% (Sentry Guns are built every 6 seconds instead of every 10 seconds), allowing up to 5 Sentry Guns per Engineer.
If NinjaKiwi goes offline, the maintenance screen will display a modified version of the BMC art for this upgrade, with the sentry gun being replaced with a faulty television.