PostHog (YC W20) started as an open source product analytics tool. Today, its AI systems are already generating a portion of the company's own pull requests, and its vision is much bigger: self-driving software that identifies product problems and automatically ships fixes. At Startup School Paris, @posthog CEO James Hawkins (@james406) sat down with YC's @t_blom to discuss why the company made that shift, how AI is changing the way software gets built, and why founders consistently…