Workers
Workers are responsible for performing tasks such as building new tiles and constructing new systems. The player will determine how many Workers they need, and Workers will arrive to fill those roles; how quickly will be based on how happy the current set of Workers are. Worker Happiness is based on salary in addition to the other factors, with higher salaries increasing Worker Happiness.
If a Worker's Happiness falls below -5, they will quit and attempt to leave the station.
If a player lays off at least 10% of their work force or at least 4 Workers (whichever is greater), all remaining Workers will immediately lose some amount of Happiness based on what percentage is laid off. In other words, if a player changes their desired number of Workers to a number below their currently-employed Workers, the "excess" Workers (chosen at random) are considered laid off. This penalty cannot be erased by hiring more Workers, but other factors can restore the lost Happiness over time.
Hiring Workers
The player has 3 options when it comes to hiring workers, and they have to balance the pros and the cons of each as they play.
1) Using a Placement Agency
Placement agencies typically have a number of applicants available immediately, but hiring one requires paying the agency a fee. Applicants are pre-screened, so the worst are not in the pool, but the best applicants know they don't need an agency, so they aren't in the pool either; the result is that while using a placement agency will let you hiring someone quick, you'll get a middle-of-the-road worker rather than potentially finding the cream-of-the-crop.
Once hired, workers typically need a day or two to travel to your station before they can begin work.
2) Hiring Directly
You can post a want ad yourself to avoid the placement agency's fees. This however requires several days before you have a pool of applicants to choose from, and the range of quality runs the full gamut from the virtually unhirable to the absolute best worker you could have dreamed of. Additionally, once hired, workers typically need a few days before they show up at your station.
Should you leave the ad open instead of hiring someone, the pool will change over time as applicants withdraw or apply, so it you don't like what you've got you can always just keep waiting. You can also give your pool a slight quality boost by promoting it for a variable fee.
3) Using a Recruiter
If you have both time and money to spare, you can find the perfect fit for your needs by using a recruiter. This allows you to specify the skills you want, and your recruiter will go out and find the perfect fit. This takes longer the more skills you require and the higher your require them, and when the recruiter returns you only have a single applicant to look at.
Should you decline to hire the recruiter's applicant, you can continue the search for a smaller fee, or terminate the contract.