Inventory is often delivered to warehouses in shipping containers. But what if you took the warehouse out of the equation and just built a fulfillment center inside the container itself? That's the vision of Shotput, a San Francisco-based startup that's looking to turn the traditional fulfillment model on its head.

Designed for fast-growing e-commerce companies, Shotput's model would offer an alternative to building out a traditional warehouse network. Instead of contracting for fixed storage space, an e-tailer could simply arrange to have a "micro-warehouse" installed in a location close to its customers and use high-end automated systems to fill complex orders on the spot.

Shotput assembles these robotic micro-warehouses itself using off-the-shelf components. Each container is outfitted with pressure-sensitive shelves equipped with radio-frequency identification (RFID) receivers that can monitor inventory in real time. An end-of-line "autobagger" system allows multiple items to be packed in prelabeled bags by the system's built-in robot, according to company CEO Praful Mathur.

The company plans to ship these micro-warehouses to manufacturers, which will stock the shelves directly, then send each container to the desired location via truck or rail. Once the micro-warehouse is in place, retailers could contract with local carriers to pick up parcels from the unit and deliver them to nearby homes.

The company says its aim is to help users develop sophisticated fulfillment services on par with Amazon Prime's. Shotput is backed by investment funding from the Mountain View, Calif.-based startup incubator Y Combinator and venture capitalist Justin Kan. The firm is now working on a pilot project that's expected to go live by early 2018 and plans a public launch in 2019.