AI makes tech debt more expensive

"Companies with relatively young, high-quality codebases"

I thought that at the beginning the code might be a bit messy because there is the need to iterate fast and quality comes with time, what's the experience of the crowd on this?

I don't think there's such a thing as a single metric for quality - the code should do what is required at the time and scale. At the early stages, you can get away with inefficient things that are faster to develop and iterate on, then when you get to the scale where you have thousands of customers and find that your problem is data throughput or whatever, and not speed of iteration, you can break that apart and make a more complex beast of it.

You gotta make the right trade-off at the right time.