If you’re a software developer or engineer, mastering an in-demand specialization such as machine learning can translate into a considerable compensation bump. But how much do some of these specializations actually pay?

For an answer, we can turn to levels.fyi, which crowdsources compensation data. While crowdsourcing isn’t always the most scientific means of determining data-points, it’s often a good way to evaluate trends. Based on the website’s findings, understanding the intricacies of machine learning, blockchain, and augmented reality (AR)/virtual reality (VR) can lead to some of the biggest paydays:

One important note: mastering any specialization takes time, resources, and commitment. For example, if you want to learn the intricacies of DevOps, you’ll need to know CI/CD, automation, testing tools, Agile and Scrum methodology, ITIL, DevSecOps, and much more. Becoming a blockchain-focused developer, meanwhile, demands knowledge of blockchain (duh), Distributed Ledger Technology (DLT), the principles of smart contracting, and so on. (It’s also helpful to compare this levels.fyi list to Indeed’s recent list of the “best” jobs in the U.S.—you’ll note a good deal of overlap for topics like machine learning and data science.)

Fortunately, online learning platforms such as Coursera and Udemy often teach these specializations. For those who like to learn on their own, there’s almost always a lot of documentation and self-guided tutorials available via the web—w3schools is a good place to start for many disciplines.

Whatever your career path, also keep in mind that keeping your skills up-to-date is arguably the most important thing you can do. The tech industry is constantly evolving, and those who stay atop the latest tools and tricks for a particular specialization have the highest chance of landing the jobs of their dreams. Also pay attention to how your specialization can lead to different career paths, such as consulting, teaching, or even the C-suite; once you develop a reputation as a skilled practitioner, you’ll hopefully have your choice of opportunities.