Vibe coding got expensive because the loops add up, and Amazon’s Darko Mesaros says Kiro’s spec-first approach cuts them short

Hand a coding task to an AI agent today and it keeps going on its own. It writes the code, runs the tests, reads the error it just caused and tries again. There is a name for working this way, vibe coding, where the developer describes what they want in rough terms and lets the model fill in the rest. Developers now spend more of the day watching that than typing.Every one of those loops is billed, and they do not add up in a straight line, because each attempt drags along everything the agent read before it. Ten tries cost more than ten times one try. A flat monthly fee used to absorb that. This year nearly every major coding tool switched to charging for what gets used, and the sums became the developer’s problem.Darko Mesaros has spent much of the past year arguing developers off that habit. A distinguished developer advocate at AWS, he spends his week in front of developers,…