Because I’ve been a software engineer for over 20 years. If I look at a feature and feel like it will take me a day and an LLM churns it out in a hour including the iterating, I’m confident that using the LLM was meaningfully faster. Especially since engineers (including me) are notoriously bad at accurate estimation and things usually take at least twice as long as they estimate.

I have tested throwing several features at an LLM lately and I have no doubt that I’m significantly faster when using an LLM. My experience matches what Antirez describes. This doesn’t make me 10x faster, mostly because so much of my job is not coding. But in term of raw coding, I can believe it’s close to 10x.