For many technologists, knowing your way around a cloud platform such as AWS or Azure is key to your job. As more businesses migrate functionality to the cloud, reliance on these platforms will only increase. But which platforms do technologists use the most?

To figure out an answer to that question, we can turn to the latest edition of Stack Overflow’s annual Developer Survey, which asked developers which cloud platforms they used the most. The following chart is based off 62,061 responses worldwide: 

As you might expect, AWS is the clear winner here. What’s surprising, though, is how Google Cloud Platform is neck-and-neck with Microsoft Azure. For years, Google’s cloud was widely viewed as a distant third-place contender behind AWS and Azure. However, under the leadership of Thomas Kurian, Google Cloud has seen its revenue (and employee count) radically increase. A recent Bloomberg article attributes that success to Kurian nurturing Google Cloud’s sales arm and client service; his current challenge is to make the division profitable. 

Meanwhile, Azure has become Microsoft’s growth engine, with revenues rising at a rapid clip. As Azure adds more features, it puts additional pressure on AWS—which long enjoyed a first-mover advantage in the cloud space—to upgrade its own offerings. In theory, clients will ultimately benefit from this competition, provided it actually drives prices down.

This chart also shows the significant challenges facing IBM and Oracle in this space. These tech giants once dominated the world of the on-premises tech stack; their transitions to the cloud have been considerably more fraught. A relative latecomer to the cloud-infrastructure market, Oracle has spent years (and a lot of money) trying to catch up to Microsoft, Amazon, and Google. Leveraging its strengths, IBM is currently focused on “specialty clouds” for demanding industries such as financial services—which may earn it revenue, but not overwhelming market-share. 

If you’re interested in learning more about cloud services, it pays to study their current features and certifications. For example, AWS and Azure offer a variety of certification tracks that will assure hiring managers you have what it takes to operate them. As you explore cloud-related jobs and career tracks, keep in mind that many companies have very specialized uses for cloud services and infrastructure; even if you think you’ve mastered a platform, you may have to learn a totally new feature in order to serve a company’s goals.