Software firm 37signals has begun moving its data stored on Amazon Web Services' (AWS) Simple Storage Solution (S3) out of the cloud.

37signals CTO David Heinemeier Hansson (DHH) posted on LinkedIn yesterday to announce that the company was entering a new phase of its cloud repatriation effort.

First reported by The Register, DHH said that 37signals had been on AWS S3 for more than a decade.

"It's finally time to say farewell. We're just about to start moving our many petabytes of storage for Basecamp, HEY, and all the heritage apps onto our new Pure Storage flash beast," DHH wrote.

The CEO estimates that the company will save around $1.3 million annually by ditching its S3 hosting commitment.

The migration will see all storage moving to 18 petabytes of capacity that 37signals bought from Pure Storage which will be hosted in 37signals' two data centers. DHH said that the company's AWS storage bill was in the realm of $1.5m annually, while the Pure Storage solution will cost less than $200,000.

DHH added: "Fair play to AWS for comping the quarter of a million-dollar egress bill, per their public commitments. It took a while to get it approved, but in the end, we got it."

DHH previously said that its remaining use of AWS was for 10 petabytes of data stored on S3.

AWS globally removed data transfer fees for customers looking to exit its platform in March 2024, motivated by the European Data Act, which requires cloud providers to remove "obstacles to effective switching" between their own and competing cloud services, including commercial, contractual, technical, or organizational hurdles - and by extension egress fees.

37signals has been working on ditching the cloud - and specifically AWS and Google - since 2022, when DHH revealed that its annual bill was exceeding $3.2m.

In October 2024, 37signals estimated that it had saved $2m that year by exiting the cloud.

Part of the migration project saw the company spending around $700,000 on the new Dell hardware, which was "entirely recouped during 2023 while the long-term commitments slowly rolled off."

DHH has estimated that the company will save more than $10m over a five year period.

While these savings seem dramatic, the comparison made seems to be solely in terms of the upfront cost of the new hardware from both Dell and Pure. The estimates don't seem to take into account the costs of hardware refreshes, additional operations roles that have to be created as a result of bringing hardware back into 37signals' remit, and the cost of running data centers in general in terms of power, cooling, leasing etc.

Another well-known cloud repatriator is DropBox, which in 2016 decided to move back to operating its own data centers.