You got your degree. You got a job. And you're pretty good at that job. But lately you've been watching kids just out of college command salaries that are edging too close for comfort. Why?

The world — especially the technical one — is changing fast. Finding people with the skills to manage large sets of data, program in the latest language, or speak to the latest influx of non-English-speaking staffers is hard, and companies pay more for employees who can do it all. Fortunately, going back to school to get the skills you need to become one of those rare creatures is not hard. Log on from your phone and watch a lecture. Take a test on your commute. Most of this online learning is free or available for a low monthly fee, and it can really pay off.

We tracked down seven classes voted most likely to fatten your paycheck.

Slide 1: SCALA

SCALA is a programming language that runs on the Java platform. It's popular with just about everyone who builds software that handles large amounts of data. And, no matter what your job is, according to Payscale and Money magazine, knowing how to use SCALA could boost your salary by about 20 percent. If programming is — or could be — your jam, you can learn SCALA for free at Edx.org ($50 will get you a certificate proving you passed) or for $50 a month (after a 7-day free trial) at Coursera.

Slide 2: SAS

SAS is a statistical analysis software. And, according to Payscale, knowing how, why, and when to use it could get you a significant pay bump. You might think you need to work in finance for this to matter. Apparently, that's not so. Even people working in marketing and other fields were more valued, and earning more, after they got nerdy and learned to analyze some data. You can do a series of courses on SAS programming at Coursera for $49 a month.

Slide 3: Project management

According to jobs site The Ladders, understanding project management is a fast track to earning 20 percent more money than the average employee. It's not easy, though, as you know if you have ever tried to herd kittens. Passing the test that gets you the official certificate is a challenge you'll want to study up for. At EdX.org, you can earn a MicroMasters in the topic or get your feet wet to see if this is for you with one overview class. At Coursera, you can get the official Project Manager Certificate after taking a 6-month specialization class, or just find out what it's all about with the introductory class.

Slide 4: Data science

A few years ago, the data science field didn't really exist. But now every company is drowning in data, so every company needs someone to make sense of it all. People who have the requisite skills are hard to come by. Those who understand data science and are able to explain what it is often command enviable salaries. If you have a background in any kind of science or math, upping your skills to fill this role and redefining yourself as a data scientist could boost your earnings considerably. At EdX.org, you can earn a MicroMasters in the subject. Not ready for that sort of commitment? Take an intro class at Alison for free to see if digging data is your destiny.

Slide 5: Digital marketing

In the digital age, everyone needs to market what they do online. It doesn't matter if you're selling a book, a class, a restaurant meal, or your embryonic ability to program in SCALA — you have to manage Google ads, search engines, social media, and everything that goes along with reaching web customers. If you are the one at work who can do this, you will rule. And, fortunately for you, you can learn a great deal for free in Google's bite-sized classes on digital marketing in the Google Digital Garage.

Slide 6: Learn a language

Learning a language can increase your earnings in just about any field. It might also make you smarter. Studies have found that people make better decisions when they consider their options in a language other than their native tongue. Learn a second language! You will be smarter and richer. The harder question is which language to learn. If money is your motive, experts say you will get the biggest pay bump by learning German and the smallest by learning Spanish. But this all depends on the supply and demand in your field and location. In some parts of the U.S., a lot of people are fluent in both English and Spanish, which means there is no supply problem. But if your workplace needs to communicate in Spain, learning German won't help. Once you decide which language to try, the actual classes are fun — and free — at Duolingo.

Slide 7: Conflict management

According to online learning site Udemy, the top soft skill employers are seeking is called "conflict management." You may be looking around your workplace and nodding in agreement right now. (Or hiding in the broom closet to avoid the fray.) If you are seeking a promotion or hoping to make yourself so invaluable that you can ask for a raise without fear, this may be the skill to cultivate. Companies spent $359 billion in paid hours in 2008 on mitigating conflict. Most recognize this is a necessary part of getting things done with humans. But they do care about how conflict is handled, especially if it leads to productive outcomes. Be that guy. The consiglieri everyone turns to for resolution. You can take a class in it at Udemy for $50.