In the country’s major tech hubs, employers with open jobs are scrambling to find the talent they need at the best price. And that’s often an absurdly difficult task, given the tech industry’s notably low unemployment rate. But which jobs are hardest to fill?

For technologists in those tech hubs, that information is useful because it gives them a little bit more leverage in any kind of salary or compensation discussion. Even if a company isn’t willing to pay you more money, your future manager and HR department might prove amenable to giving you more PTO, remote-work options, or a more flexible schedule.

The good news is, the most common and hardest-to-fill jobs aren’t limited roles such as artificial intelligence (A.I.) researcher. When we analyzed New York, San Francisco, Boston, Seattle, and Austin, we found that the hardest-to-fill job was software developer/engineer, followed by IT project manager, with computer support specialist coming in third. Lots of folks have those jobs, and their skills are needed.

(For this exercise, we used Burning Glass, which collects and analyzes data from millions of job postings around the country. To assess “hard to fill,” Burning Glass relies on four metrics: time to fill a position, number of job postings, salary, and “location quotient,” which is a measure of “concentrated” demand for a role within a particular geography.)

Here’s the full list of the top 15 roles:

The roles on this list should come as no surprise. Although companies are quick to tout their interest in machine learning and other cutting-edge technologies, they always need technologists who can maintain legacy infrastructure and apps while creating products that consumers need right now. That’s why developers, engineers, and architects top this list, along with multimedia designers and webmasters.

While both the largest tech hubs and many up-and-coming tech cities have attracted a lot of negative attention over their high cost of living, a recent study from Indeed suggests that such fears about urban costs might actually prove overblown. “Even after adjusting for those costs, tech salaries are still 5 [percent] higher in the largest metros than in the smallest ones,” Indeed reported. “And tech salaries in metros between 250,000 and 500,000 people are higher yet—and nearly the same across mid-size, large, and very large metros.”

Of course, things might be a little different in San Francisco, one of the cities used in our analysis, given its much-publicized issues around housing costs and livability. In any case, check out Indeed’s salaries chart, which mixes "big" tech hubs such as Boston with rising ones such as Raleigh, NC.

Take the data from Burning Glass and Indeed together, and it’s clear that tech hubs are still hungry for technologists, and often paying out salaries that make those cities livable. But that doesn’t mean just anyone with a modicum of programming knowledge can sweep through and expect to land a job at a major tech firm (with a handsome salary to boot). If you want to stand out, specialization (and a record of skill) is key, especially in areas such as cybersecurity.