Ask HN: How to Find Experts?

Why not try those who started the projects you are interested in? Perhaps some or all of them will contract their time, especially if it is really such a short duration, but don't expect it to be cheap.

Via searching github forks of these projects or searching in Google for related blog posts, etc. you might find others who are actively involved that you could contact.

If you are that unsure of your code though, perhaps you should contract/hire someone a little more surefooted to work longer than a few hours? There are a number of Ruby/Rails contracting agencies, which is where I'd start. Maybe places like:

http://www.mirrorplacement.com/

Or find someone in: http://workingwithrails.com/

Just search- you should find a number of them.

On some project mailing lists, you are allowed to post jobs like this. Some project sponsors even support this behavior with a dedicated job board website.

But: each project has different policies, and may even not have a policy if it's that new and no one has asked your question before. So write a polite email to the list asking if it is OK to post a help wanted job ad, and if yes, what are the guidelines. Do NOT include your job ad in this question email. If you get the all clear, fire away.

Another idea would be going to local meetups in a related technology.