Over the 15+ years I’ve been hiring engineers in Silicon Valley I have worked with at least a dozen recruiting firms. OSI is by far the best I have worked with, and is now the only one I use. OSI consistently understands my requirements and sends resumes that are thoughtfully appropriate for the roles. They never have spammed me or my managers with inappropriate resumes. They do not shy away from very difficult searches. They are exceptionally responsive to email and understanding if and when requirements need to change. I can enthusiastically recommend OSI as the best recruiter in the valley.