On any given web page, there are 11-15 places you can apply your SEO strategy, and if you write the body of text for humans, there will be sufficient keywords in the body of the text to do what you need.

If you are promoting your jobs on services like Google for Jobs, you also need not worry so much about SEO for the vacancy itself, because the job will be on the Google for Jobs platform.
 
However, in job types where there is high competition, there will be a definite need for you to boost the authority/trust of your website, as it has a clear effect on how high your jobs rank in the Google for Jobs results.
 
Boosting trust and authority is still about link building for your website, but the way in which you link build is now under more scrutiny than it has ever been. The accepted present-day wisdom, as this tip is written in June 2019, is that you need to generate your links through the provision of high-quality content that will lead to high-quality links, not volume links. Volume links are very much a yesteryear approach to SEO.