Customer IO vs Duolingo

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

Customer IO (rank #165) holds a narrow lead over Duolingo (rank #338) on the overall Smoower ecosystem score (51 vs 43). The gap of 8 points reflects composite signals across code, docs, community and reach.

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

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. Duolingo shows 1,721 stars across 12 public repos, 8 active in the last 90 days and 11 external contributors.

Customer IO is the stronger read for anyone weighting education. Duolingo looks better where reach 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.