There is no easy out, if you really need to scale, regardless of infrastructure you are going to need someone who understands databases. If you're lucky you might be able to find someone who can do more than one job. e.g. dba+sys admin. Just make sure that they really do know both things.
Yeah, this kind of question seems really close to "I'm a business guy, all I need is a tech guy to implement my idea", which implies there's some way to avoid having to know how to do something that is core to the business.
For that you use an embedded database system. Many enterprise apps come with embedded database systems, or require a major database system to be installed in tandem, and these things are targeted at medium sized companies that don't have DBA specific to the the department that is using the app.
or explicitly tell them how to configure their system, and what kind of a system to run it on. this doesn't help you avoid a dba, it merely avoids them having one.
