You just need a raise, not a degree in rocket science. And in some cases, getting a certification or taking an online workshop is enough to freshen up your knowledge on a topic. For deeper dives in-demand skills, like coding, consider free or low-cost online classes you can do in your spare time (and pj’s); try the ones offered by LinkedIn Learning, edx, and coursea. If you learn better in a brick-and-chalk-dust setting, look into extension programs at nearby colleges. The tuition might not even come out of your wallet, of your employer pays for continuing education classes. “In today’s workforce, the most valuable employees have expertise in a variety of topics,” says Karen Shnek Lippman, an executive recruiter based in New York City.