Years ago at a previous job my boss donated a CAD workstation and some CNC time to the local public highschool's robotics team, then coordinated with their supervising teacher to have a couple employees (including me) mentor there one afternoon per week for the school year.
As a mentor, I helped students understand compiler errors, recommended writing a function instead of repeatedly typing the same code, and also gave more advanced advice, like explaining how PID loops could prevent gears from stripping. It was rewarding to see these students both grow and enjoy the learning process.
It also paid dividends for my boss when some of these students applied for summer internship at our company, which eventually led to several excellent full time hires after college, including referrals our interns had made to their fellow engineering students.
While it took a couple years to pay off, those few hours of community service introduced us to quality people that no jobs board could have.