Besides a focus on generative AI, what do AI startups like OpenAI, Anthropic and Together AI share in common? They use Stainless, a platform created by ex-Stripe staffer Alex Rattray, to generate SDKs for their APIs.

Rattray, who studied economics at the University of Pennsylvania, has been building things for as long as he can remember, from an underground newspaper in high school to a bike-share program in college. Rattray picked up programming on the side while at UPenn, which led to a job at Stripe as an engineer on the developer platform team.