If you’re applying for a job as a software engineer, you might wonder which associated skills will make you most attractive to future employers. Knowledge of some ultra-popular programming languages can also give you an advantage during the job hunt.

In order to narrow down those skills, we can turn to Burning Glass, which collects and analyzes millions of job postings from across the country. Based on that data, employers obviously want engineers who’ve mastered the principles of software engineering and development (including, presumably, soft skills such as communication). Beyond that, though, there are several programming languages and tools popular at companies right now:

That Java, Python, and JavaScript top this list should come as no surprise; even if companies are currently using newer languages such as Swift, TypeScript and Kotlin to build the next generation of apps and services, there are mountains of legacy code that must be updated and maintained. SQL, a programming language designed for managing and querying relational databases, is likewise important to know, given the number of software engineering projects that intersect with company databases. And knowledge of Scrum and Agile is always helpful, as teams expect new software engineers to slip seamlessly into the workflow.

With tech unemployment at historical lows, companies everywhere are hungry for software engineers with the right mix of skills and experience. Low unemployment can also translate into more leverage for job candidates, which can often mean higher salaries and great benefits. At larger companies with substantial budgets, experienced engineers can easily earn six-figure compensation—but even smaller organizations without that kind of money for salaries are usually willing to negotiate on perks and benefits such as flexible schedules.