A forecast predicts that AI systems will perform most software development because their output will be commercially acceptable at far lower cost, even when it falls short of the quality expected from human-led engineering. It expects businesses to accept software with “99.99” quality rather than “99.999” quality when the cost difference is substantial, and predicts that consumer expectations will adjust accordingly. The forecast also predicts that software engineering outside AI development will slow sharply rather than continue producing broadly adopted new technologies. It argues that developers will have little incentive to create UI libraries when state-of-the-art models are strongest in React, or to create programming languages when those models already know Python, Go, JavaScript, and other established languages best. New libraries and languages may become easier to create, but the prediction is that they will struggle to gain adoption. Large corporations may be exceptions because they can train or fine-tune models on internal technologies, although those technologies could still face difficulty building external communities and talent pools when outside developers lack access to the companies’ models or do not want to use them.