Amazon has become a logistics and transportation powerhouse, so much so that the company now handles half of its own deliveries worldwide. And numerous Amazon employees are taking the expertise they’ve developed at the e-commerce giant to startups that aim to help other companies ship products to customers faster.

Those startups, which include FreightWeb, Convoy, and Flexe, are drawing a fast-growing amount of venture capital investment. VC firms poured $2.03 billion into logistics startups this year, according to PitchBook. That’s more money than in the prior seven years combined. The number of deals has nearly quadrupled in the same time frame as well.