Many AI apps today feel like the "horseless carriages" of the late 19th century, which "swapped a horse for an engine without redesigning the vehicle to handle higher speeds." They pack powerful tech into outdated interfaces. YC's Pete Koomen (@koomen) thinks we can do better. He joined @t_blom and @dflieb to lay out a new vision for how AI should actually work: not as a chatbot bolted onto legacy software, but as a customizable tool that helps people offload the work they don't want to do. From editable system prompts to agents that act more like collaborators, they break down what it means to build AI-native software—and why the future belongs to products that let users teach machines how they think. 0:00 – Intro 0:52 – Why AI apps are broken 2:39 – How Gmail’s AI features fall short 4:00 – A better way to build AI apps 5:27 – The hidden system prompt 7:57 – What if you could access the system prompt? 9:40 – The developer-user divide in software 10:48 – The "horseless carriage" metaphor 13:35 – Email reading agent demo 14:34 – Everyone can be a prompt engineer 16:23 – Why coding agents feel magical 21:42 – Training AI like a human assistant 28:45 – The problem with chatbot interfaces 29:10 – Advice for founders