I've been looking for Shopify job search themes and apps but without success. Eg, an employer can post vacancies and a registered candidate can look and select the job and contact employer through website or apps. eg https://www.jobsite.co.uk/
I'm not sure I fully understand the end goal, so I was hoping i could clarify what you've wrote above. Are you looking to add a job listings feature & search onto your Shopify website to hire potential applicants for your business? Or are you hoping to create a "job bank" type website with Shopify where users can browse and apply for jobs from a variety of different businesses?
With some more context, I can help point you in the right direction!
This project is possible to do it, but take in mind that customers can't create products without using a custom App (we are supposing you will use the jobs as products), so employers must contact you to create the job.