Rather than access data from networked hard disk drives, Instagram's server instances on EC2 can use directly connected solid-state disks, said Mike Krieger, a co-founder of the company that Facebook agreed to acquire in April for about US$1 billion. Instagram got trial access to solid-state drives on the EC2 cloud-computing platform before that option became generally available, one of the perks of being a large customer, Krieger said.

Enterprises are starting to embrace SSDs as a faster, more compact and less power-hungry alternative to spinning disks, though the hardware still costs more per gigabyte. Web 2.0 services such as Instagram have been early adopters of the technology.

Krieger would not estimate how much data Instagram maintains, but he said users have uploaded about 5 billion images to the service.

Instagram turned to EC2 early in its life in order to deal with rapid growth. It had launched with just one rented server in Los Angeles, Krieger said.

"We planned very poorly in the beginning," Krieger said. Other tech startups based near its San Francisco headquarters recommended using EC2 for flexibility in infrastructure, and Instagram has been happy with the service ever since, he said.