Here is your Forbes Daily Briefing for Tuesday, March 17th.

Today on Forbes, meet the $9 billion AI company reimagining vibe coding.

Two years ago, Replit CEO Amjad Masad invited Paul Graham, the legendary co-founder of the startup incubator Y Combinator,

to his home office near Palo Alto, California, to give Graham a sneak peek of Replitt's new

and novel product, an AI agent that could write its own code. It was the first time Graham had

seen what would become known as vibe coding. Graham recalls,

quote, the name hadn't even been invented. As the agent got to work building apps, Graham, a lifelong

computer programmer, instinctively looked at the code. Masad scolded him, saying there was no need,

arguing that the source code would only be an unimportant byproduct, and programming would now be done in English.

A radical change for software engineers. Graham, one of Replett's earliest investors,

tells Forbes, quote, it was mind-bending. He's bald with that beard, and I think he was actually

wearing a black turtleneck. I felt like he was a bond villain. Ha ha ha, don't look at that code.

Now vibe coding, of course, is everywhere, and Replit is looking to take it a step further.

Last week, the startup announced its new agent, simply called

Agent 4, which aims to deliver a new type of interface for vibe coding. Like last time, Massad

demoed the new agent to Graham at his home office in early March. After the meeting, Graham gushed

about the product on X. He posted, quote,

Amjad showed me Replit's latest stuff.

They're about to redefine vibe coding in a way that will seem obvious in retrospect.

A lot of the biggest ideas have that quality.

Instead of just typing in prompts to instruct the agent on what to code,

Replet offers what it

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