Case studyUpdated 2026-04

37signals: leaving the cloud, what egress cost

In late 2022 David Heinemeier Hansson announced 37signals would leave the cloud. The company published its costs publicly: an estimated $3.2M / year spent on AWS and Cloud Run, with ~17 percent attributable to data transfer charges. The migration to on-premises hardware (Dell servers in two colos) completed in 2024 and reportedly delivered ~$2M / year in savings.

Sources: DHH: We have left the cloud, Basecamp cloud-exit posts.

The documented cost breakdown

From 37signals public posts (DHH blog Feb 2023 and Oct 2023):

HEY (email service) was running on roughly $90k / month of AWS.
Basecamp and other applications added approximately $165k / month across AWS + Google Cloud.
Total annual cloud spend: ~$3.2M.
Data transfer charges were called out as a meaningful component, with DHH specifically citing $0.09/GB AWS egress on services that did not benefit from CloudFront caching.
The migration target hardware: ~$700k in Dell servers, expected useful life 5+ years, amortising to ~$140k / year + power + colo + DCO labour.

What changed with the EU Data Act free-egress in 2024

In March 2024, AWS announced free egress for customers leaving AWS, tied to the EU Data Act compliance window. 37signals could not have used this when they planned the exit in 2022-2023, but a similar exit today would have the option to apply for free-egress under that programme. The conditions:

The customer commits in writing to terminate the relevant AWS services.
The migration completes within an agreed window (typically 60 days).
Only internet egress is waived. Cross-AZ, NAT processing, and other charges still apply.
Once the data has moved, you cannot resume normal use of the services without losing the waiver retroactively.

For a full-account migration like 37signals, this would have been a material saving. For multi-cloud or hybrid architectures that keep AWS active, it offers little. The waiver is designed for switching, not for ongoing optionality.