37signals vs Klaviyo

37signals (HEY! It's in Basecamp!) and Klaviyo both appear on the Smoower Developer Ecosystem Index.

37signals (rank #122) holds a narrow lead over Klaviyo (rank #237) on the overall Smoower ecosystem score (54 vs 48). The gap of 6 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), 37signals is slightly ahead of Klaviyo. On education (docs, guides and learning material for developers), Klaviyo is slightly ahead of 37signals. On community (issue response, PR reviews and discussion health), 37signals is slightly ahead of Klaviyo. On reach (how visible the ecosystem is beyond its own repos), 37signals is ahead of Klaviyo. On momentum (release cadence and how fast the ecosystem moves), 37signals is ahead of Klaviyo.

37signals carries 113,857 GitHub stars across 236 public repos, with 48 repositories active in the last 90 days and 298 external contributors on record. Klaviyo shows 573 stars across 117 public repos, 23 active in the last 90 days and 17 external contributors. The star gap on its own does not decide the comparison, but 37signals's footprint is roughly 198.7x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

37signals is the stronger read for anyone weighting reach. Klaviyo looks better where education is the deciding factor. The table below breaks the scores down pillar by pillar; the linked profiles cover the underlying repos, docs and community signals in full.