Ask HN: How do you motivate your team to work on mundane tasks?

At my company, part of product involves on-boarding new developers (freelancers) on the platform and evaluating their profile and the online coding assessment. We are not at a stage where we can have a separate team of evaluators to take care of this so our tech team is required to set aside time from their coding work and evaluate these profiles, which is a mundane and non-rewarding work for them. How do you keep your team motivated to do such mundane tasks that are important for the company/product and yet not directly related to their individual performance?