Apologies if this has already been suggested; I couldn’t find this anywhere.
It seems that currently, you as the airport CEO are in charge of hiring individual employees for airport staff, ground crew, security, janitors, and maintenance people. At least in the US, this isn’t very realistic. For security, airports contract with the TSA or private security firms who provide security service for a set price. This could be implemented by adding security contracts, where companies agree to provide security for your airport for a set price. To make it more complex, you could make it so there are factors other than price that differ by contract, such as who provides the equipment and necessary accommodations for the employees.
The same is true for maintenance and janitors. These jobs are often contracted out.
For ground crew and airport staff, most of these jobs are done by airline employees. For example, manning the check in desk and the boarding desk, some information desks, and handling the bags. I understand that the airline contracts aren’t yet like how they are in real life, so maybe this is planned for when the contract system is updated.
I know some people enjoy having it how it is now as it gives them more control, but I would like to see there be some of these options for people who don’t want to micromanage everything. For things that are usually contracted out, we could have the option to contract them out or to do them in house and hire the employees to do so. For things traditionally done by airlines, who does them could be a negotiable part of the contract. If you don’t want to deal with them, you could insist that the airlines do them, which would come at a cost and possibly losing out on some contracts. For people who like to micromanage things, they could negotiate to do it in-house which would result in a larger cost to the airline.