Customer IO vs KAYAK

Customer IO and KAYAK both appear on the Smoower Developer Ecosystem Index.

Customer IO (rank #165) holds a modest lead over KAYAK (rank #485) on the overall Smoower ecosystem score (51 vs 38). The gap of 13 points reflects composite signals across code, docs, community and reach.

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

Customer IO carries 684 GitHub stars across 107 public repos, with 42 repositories active in the last 90 days and 26 external contributors on record. KAYAK shows 3,186 stars across 72 public repos, 4 active in the last 90 days and 1 external contributors. The star gap on its own does not decide the comparison, but KAYAK's footprint is roughly 4.7x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Customer IO is the stronger read for anyone weighting education. KAYAK looks better where code quality 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.