<OT>
I doubt that senior developers would want to work for somebody who can't even spell.
And don't say that English is not your mother tongue, because spell checkers work for foreigners (like me) as well.
If you want to attract senior developers, try looking a little bit more "senior" yourself.
</OT>

Update
That was free advice. It may look blunt, buth it's truthful. Don't discard it just because it hurts.

That aside, check dws home node for some specific advice, such as On Interviewing Candidates and An Interview Quandry.