Facebook has pulled billions of Instagram pictures from Amazon’s cloud computing service and transferred them to its own data centers.

It has emerged that the social media giant has moved over 20bn photos from Amazon web services (AWS) in the last year.

Picture-based social media service Instagram has been run entirely on AWS since its inception in 2010. It ran on cloud computing service Amazon EC2, which enabled it to build and run its own software without needing its own servers.

The mobile photo sharing service was bought by Facebook in April 2012 for approximately US$1bn in cash and stock, after which its annual rate of growth (23%) has outpaced that of owner Facebook (3%).

Although Facebook has bought and integrated companies before, this was by far its biggest project, it said, as Instagram has 200m users.

The mass migration has been carried out without any disruption to the service, according to Instagram founder Mike Krieger.

“The users are still in the same car they were in at the beginning of the journey, but we’ve swapped out every single part without them noticing,” Krieger said.

Facebook said that the project has helped it create a template for merging its data center operation with any apps it may acquire in the future.

The process involved creating a copy of the software behind Instagram and running it on the platform while the data - both personal information and the 20bn photographs taken by all users - was being transferred.

The migration used Amazon’s Virtual Private Cloud and the complete process took a year, tying up between 8 (initially) and 20 (eventually) members of the Facebook data center team. Preparations took 11 months while the data transfer was achieved over the course of a month.