High-traffic, Highly-secure web API, what language? [closed]

Question

If you were planning on building a high-traffic, very secure site what language would you use?

For example, if you were planning on say building an authorize.net-scale site, that had to handle tons of credit card transactions via an API, what would you use building it from scratch? I would imagine that most sites handling similar traffic with similar security would use non open-source software (correct me if I'm wrong). What open source software would you use and why? Python, Ruby, Erlang, PHP, custom C/C++, or what? Also, would you use a traditional database, or does the NoSQL route make more sense?

Not trying to start a flame-war here, just wondering what the good people of Stack Overflow think on the subject...

Update: As a bit of a clarification, this is entirely hypothetical. I fully understand the importance of knowing your language/platform, just looking for some opinions of strengths/weaknesses of a given language/framework and where (and why) one might be more suitable over another. As far as data goes, I'm thinking customer A bought items X, Y, and Z, from vendor B. So, pretty straightforward, until someone wants to know whether customer C also bought items X and Y or X and Z or Y and Z together in one purchase. So, from a data standpoint, I guess I'm looking at it from a business intelligence standpoint and wondering whether NoSQL has any advantages/disadvantages over a traditional SQL database.

Answer 1

I would choose the one I know the best. In my individual case it will be most likely Java of some sort.

Answer 2

Building high-traffic sites is more about design and architecture than the language. Consider the experience of your team, the availability of third-party libraries you might need, and choose wisely.

You can use a NoSQL database if you like to experiment and don't mind working with technologies that just didn't have the time to accumulate huge amount of experience as relational databases had, but otherwise I'd recommend you to go for the traditional way now.