ProgrammableWeb's directory contains many APIs for job seekers and job hiring. The APIs can aid developers who are creating recruiting applications, and provide niche job directories such as field technicians, freelancers, ministry, as well as resume scoring, background checks and much more.
SaaS and cloud services provider LiveOps has just announced the release of a new "cloudsourcing" API for its LiveWork service. The Open Workforce API (OWAPI) enables businesses to integrate applications with an on-demand virtual workforce provided by LiveWork (more at our Open Workforce API Profile).
The United States Department of Veterans Affairs has been helping veterans find employment for years. They provide job listing and educational services that are designed to make the transition a lot easier. With the Addition of the VetSuccess API, the VA is making job posting a lot easier for prospective employers.