As a recruiter you already know the biggest places to post your tech jobs and/or search tech resumes. Namely sites like Dice and ComputerJobs which have been around forever. But according to our friends at CareerCloud there are nearly 40 tech only job boards online today.
Here's some of the more general lesser known ones that you could be using but aren't. Perhaps they'll give you some additional opportunities to find those hard to find techies you so longingly wish for. :-)
1. IT Job Cafe: http://www.itjobcafe.com/
This site claims to have more than 100,000 search resumes for technical candidates. Job postings start at $149 and you can buy an individual resume for as low as 5 bucks.
2. Authentic Jobs: https://authenticjobs.com/
This site might be the best site of all these to search and post jobs. They offer a money back guarantee. They also have a sister site called "Pros" full of searchable resumes.
3. Hired: https://hired.com/employers
With Hired companies setup a profile, then search candidates to invite for interviews. they claim a 95% response rate when reaching out to candidates in their system.
4. Crunchboard: http://www.crunchboard.com/
Started by the popular tech blog TechCrunch, this job features $200 job listings.
5. Gun.io: https://gun.io/
This site matches you to top freelance developers worldwide. They say: We're so confident in our process and our community, that if you're not 100% happy with the candidates we introduce, you won't pay a single penny.
6. TopTechJobs: http://toptechjobs.com/
Formerly known as Net-Temps they have collected hundreds of thousands of temporary tech talent resumes over the years.
7. F6S: https://www.f6s.com/jobs
A tech community for startups you can post jobs for free.