If your start-up has nobody that is competent at operations (which really is a lot more engineering than IT/systems administration), it deserves to fail. Incidentally, I can tell from my personal knowledge that the "big successes" amongst Internet companies (i.e. those who have achieved a product/market fit on competitive, multi-billion dollar markets) have had a very strong operations engineer amongst either the founders of the first five employees.
If you use Rackspace to host your machine, that's an acceptable way to save money on hardware and networking gear (while you're still in the early stages).
However, you can't and shouldn't expect Rackspace's engineers do your operations for you. It is your responsibility to understand how to tune your operating system, application server, database et al. specifically to your application.
If you expect others to turn your application into an Internet service, you're analogous to a "business guy" on Craigslist posting about his "next big idea" that he wants somebody else to build.
The big point I meant to make is that if your site is down because your hosting provider is, it's still your fault (for not having a DR site).
a hacker who dabbles in IT, will never be as competent as an expert.
And bringing in an IT founder early on, is a waste of equity, since you are giving away a farm when the guy has nothing to do. + all that tuning etc, only matters when you are bringing in a ton of traffic, until then it doesn't matter if your server is 94% efficient or 97%. Worst case scenario, you throw another server into the mix.
Best software engineers are also strong systems administrators. It's also commonly understood that strong systems people must be strong software engineers. An operation department at a serious Internet company wouldn't even invite somebody who can't write production quality code for an in-person interview (they wouldn't pass a phone screen).
Strong operations people would also resent being called "IT". IT sets up corporate desktops/mail/calendaring, the VPN and mounts machines in a rack. Indeed, this could be outsourced (mail to Google Apps, rack mounting to Rackspace, OpenVPN in lieu of an expensive Cisco product).
Production operations involves something entirely different and requires an entirely different skillset. Think being able to create application specific automated provisioning, configuration, deployment, software load balancing, monitoring, fault tolerance and high availability. Monitoring is especially tricky: nearly all the enterprise and open source NMS products, for example, "get it wrong" (e.g. hyperic using a single database to store events and allowing you to only poll every few seconds). Monitoring an application (as opposed to a machine) requires writing custom code (by definition), otherwise you simply can't capture the essential vital statistics (and not just whether or not somebody listening on port 80).
I hate doing an appeal to authority, but I should add I've done operations at a very large scale (10,000+ machines) in a big name Internet company, as well as on a smaller scale at startups. I've since moved on to software engineering (since that's what I love doing the most), but it bugs me to see misconceptions about the nature of running an Internet service. Unfortunately these misconceptions run deep and often disadvantage entire application stacks by making them unfriendly to operations (e.g. the flaws of JMX).
If you use Rackspace to host your machine, that's an acceptable way to save money on hardware and networking gear (while you're still in the early stages).
However, you can't and shouldn't expect Rackspace's engineers do your operations for you. It is your responsibility to understand how to tune your operating system, application server, database et al. specifically to your application.
If you expect others to turn your application into an Internet service, you're analogous to a "business guy" on Craigslist posting about his "next big idea" that he wants somebody else to build.
The big point I meant to make is that if your site is down because your hosting provider is, it's still your fault (for not having a DR site).