Small grocery warehouses used by Instant delivery companies. From this post[1] by Tanay J

A. Dark Stores / Fulfillment Centers Instant-Delivery Apps operate their own dark stores / fulfillment centers, typically one per neighborhood they operate in. Since these are not meant for consumers, space can be used more efficiently and typically the cost to operate these (at scale) as a percent of revenue is lower than rent space for grocery stores.

https://tanay.substack.com/p/understanding-the-instant-deliv...