Businesses. Our kids use their senior year to work 2-3 days a week with the company and the other days finishing their core classes.
They then are contracted to work another year with the company out of high school then there's a couple options that companies do - most offer a full time position to those students, some offer to help subsidize further education/training opportunities.
We have students doing manufacturing, electrician, business management, EMT and more.
What I like is the apprenticeship model is there's buy in from both sides. The student gets experience and gets paid really well and companies get cheap labor and gets to mold those kids into workers they want (they get to interview all candidates)
I'm not a huge fan of internships, I've seen far too many situations where companies treat this as free labor to do menial work that didn't give the intern actual work experience