Well, he started his business in November 2015, started charging in February 2016, and hit $55k/mo by November 2016. I don't see any hyperbole/dishonesty in saying he built his business in under a year given that he actually did so. Sometimes rapid growth happens!

Of course him being able to accomplish this feat stems from skills/knowledge he acquired earlier (his blog, music industry experience, learning to code, learning to design, etc), but that's true of any business. Nobody starts from scratch, and the interviews cover people's histories pretty thoroughly.

There was no claim about yearly revenue. The figure given was $15k/mo based on $7k of sales in one week. Even so, that was a singular oversight on my part[1], not some sort of formula for all the interviews on the site.

[1] https://news.ycombinator.com/item?id=13072326