I'm also surprised, though less so, by NY's ranking -- but it's a huge diverse economy, plus has a lot of lawyers :-).
I'm from the area, but moved to SF a while back for much better engineering work. I wouldn't mind moving back some day, but haven't seen many jobs or much upward mobility that would make me want to go back. There are a lot of tech companies but they are largely smaller / regional, or are the cost centers of bigger companies (support, back office stuff).
I get the impression that's changing, though. It would be great to see ATX keep booming and reach the level of say, the Seattle tech scene.
I think Austin still lacks HQ anchors of bigger tech companies save for Dell. But the developer presence is absolutely growing.
Austin Metro is 2.17M people, Boston Metro is 4.88M. Boston is also part of the broader "Bos-Wash" chain of 50 Million people, while Texas has about 29 Million people.
Sources:
1. https://en.wikipedia.org/wiki/Greater_Austin
2. https://en.wikipedia.org/wiki/Greater_Boston
3. https://en.wikipedia.org/wiki/Northeast_megalopolis
4. https://en.wikipedia.org/wiki/Texas
Disclaimer: I'm from Austin. My friends and family really think it's a big deal... but, it's only a medium deal :)
Austin and San Antonio are close by, but there's a noticeable gap, and nearly no one lives in Austin and works in San Antonio or vice versa. Austin and San Antonio don't have the same housing prices, salaries, etc. Contrast that to a place like DFW where the boundaries all blur together and people cross-commute all over the region, and consequently they're lumped together in the census area.
To put this one last way, the census area described as Boston is about 60 minute driving radius around the central city. On the best of times you could make it from downtown Austin to downtown San Antonio in ~80 minutes, and in practice they each have distinct commuting sheds of 45-60 minutes that partially overlap around San Marcos.
Austin is great, and also it's half the population of Boston :)
It's also about institutional knowledge. It's (relatively) easy to find people in Houston who understand the value in spending $10mm to drill an oil well which has an 80%+ chance to make a single digit multiplier of your money. There's less cultural knowledge of spending that same amount of money for much smaller chance of a much, much bigger payout.
By that list Boston is #10 and Austin is #37 in the US, which matches how different the two cities "feel" in my experience as well.
I was recently in San Antonio and Austin. Both seem rather small compared to DC or Boston.
DC and Baltimore should effectively be added together into one hub and that puts it well into 3rd place and ahead of Dallas for actual urban areas.
Part of the problem is probably that LA is so close to the Bay Area - it's easy for tech talent to move up the coast or even semi-commute there instead of building a new hub.
Admittedly, I don't know what the OC startup scene is like, I've got student loans that can't be paid with equity...
A lot of talent starts in LA, but it gets immediately poached by literally every other city. If you don't have a Hollywood tech job, it's grim. I really want to stay, but can see a realistic/near future where I leave. (But I'm not going back to Irvine ever again)
In my case, I ended up just not working in LA itself for half the time I've lived here. I've spent at least as much time working in the Bay Area, Austin, Seattle, Irvine, and now Portland as I have working in LA because the companies and compensation are just so much better elsewhere.