Amazon is rolling out expanded robotics operations at fulfillment centers built on updated sorting machines, robotic arms, and its Roomba-like mover bots. The Wall Street Journal reports that Amazon’s latest inventory processing system, which the company calls Sequoia, can speed up delivery fulfillment by 25 percent and launched this week at a facility in Houston.

The new system has robots designed to work alongside humans instead of replacing them, according to Amazon. Director of robotic storage technology David Guerin says that a significant portion of its operations will use them in the next three to five years.

Notably, Amazon is testing Agility Robotics’ bi-pedal Digit robot. Here’s how Amazon describes it:

Digit can move, grasp, and handle items in spaces and corners of warehouses in novel ways. Its size and shape are well suited for buildings that are designed for humans, and we believe that there is a big opportunity to scale a mobile manipulator solution, such as Digit, which can work collaboratively with employees.

Saying there’s a “big opportunity to scale” the use of robots like Digit should be worrisome to Amazon’s 1 million human warehouse workers, despite the company saying they’re “irreplaceable.”

There’s also a new sortation and binning machine moves containers from high on shelves down to a newly designed ergonomic workstation that lines up with workers “in their power zone, between mid-thigh and mid-chest height.” This could increase safety and reduce injuries as workers don’t have to reach up or squat down for heavy items.

The building blocks of Amazon’s latest system have already been in view, as the company has discussed the developments of its warehouse robots and artificial intelligence over the last year. The company’s Sparrow robot arm can identify products inside totes and pull them out. There are also the autonomous Proteus and Hercules robots that roll around like robovacs and can lift and move shelves, distribute containers, and deliver products in the building so humans don’t have to.

Update October 18th, 2023 2:14PM ET: Added details and image from Amazon’s blog post.