Polymorph

Polymorph is a San Francisco startup (Y Combinator W26) building personalization infrastructure for consumer and self-serve software teams. It turns product behavior into live user profiles and uses AI agents to run thousands of continuous experiments, automatically tailoring the timing, channel, and content of lifecycle messaging - push, in-app, email, SMS - for each user, with clear attribution on what drove conversion. The pitch: give any team the kind of adaptive, per-user experience that companies like Meta, TikTok, and Google spend years and whole orgs building.