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What’s the most popular programming language on CodeSignal?

For engineering roles, candidates often come in with experience in a wide variety of languages. However, after thousands of assessments run on CodeSignal, we’ve noticed clear winners among the most popular languages candidates use to complete them. As part of learning the lingo, this list will help you get familiar with relevant programming languages and where they are used.

Language Popularity

Diving right into the data, here are the most popular languages used by candidates on CodeSignal:

  1. Python: 35.4%
  2. JavaScript: 22.8%
  3. Java: 15.5%
  4. C++: 6.2%
  5. C#: 5.5%
  6. MySQL: 4.3%
  7. TypeScript: 1.4%
  8. Swift: 1.3%

Let’s break this down and talk about why candidates would choose these languages.

Python comes in at number one, making up over a third of our interactive evaluations. While that’s a large percentage, it makes sense—given a choice, many candidates choose Python for its simplicity. It’s commonly known and taught, it’s applicable to many domains, and it’s easy to work with. Python programs often require writing less code than other languages like Java or C++. With its great artificial intelligence and machine learning libraries, and a robust community of specialists, Python is also popular for data science candidates.

Next is Javascript. This language is often used in web programming and mobile apps. Javascript is commonly used to build interactive frontends, especially using frameworks like React or React Native. It can also be used to build backends using frameworks like Node.js. 

Given the demand for web and mobile developers, it’s no surprise many teams need to evaluate candidates’ JavaScript skills. 

Following those are Java, C++, and C#. These powerful object-oriented languages are frequently taught in school and widely used in the workplace. Programs written in these languages can be easier to organize and maintain, so many teams use them to build large-scale systems—Netflix, Uber, and NASA’s Mars Rovers all have important services written in Java. These languages also have domain-specific uses: Java is used for Android apps, and C# is often used for Microsoft’s .NET platform or game development. 

MySQL is a relational database management system (see this article for a quick explanation of what that means), used to retrieve and process data. Within the niche of data-related assessments, MySQL is a popular choice. NoSQL databases like MongoDB or Redis have also become popular for building products, but MySQL remains a valuable skill as many teams still rely on relational databases.

TypeScript is a more powerful extension of JavaScript. Compared to JavaScript, TypeScript is object-oriented and has a variety of changes to make it more versatile. Though it’s not as popular as some other choices, it is well suited to a range of projects. 

Swift is Apple’s proprietary language for building apps within their ecosystem—most notably desktop and mobile apps. It’s commonly used in assessments of a candidate’s iOS development skills.

Accent image showing the most popular programming languages used by candidates on CodeSignal

Offering the Right Options to Candidates

For certain tasks, there’s a clear set of tools for the job. In these cases, you can use CodeSignal to evaluate a candidate’s skills in the languages you need. For instance, if you need a data analyst, you can test a candidate’s MySQL proficiency by choosing from CodeSignal’s rich library of SQL tasks.

When an assessment is more open-ended or you’re testing for general technical skill, consider providing a wider range of options. It may sound obvious, but the more popular languages are the ones candidates want to use most often. If it’s reasonable, give candidates a language-agnostic assessment using a framework-based Pre-Screen, or let them pick the language they’d like to use in the virtual onsite interview. You’ll be able to better assess their skills in a language they’re comfortable with, and you’ll give yourself access to more candidates.

Though some programming languages go in and out of fashion, the ones on this list are long-lived. We expect candidates will continue to use them for a long time to come. Where relevant, consider offering these options to candidates to let them shine. If you’re interested in using CodeSignal to evaluate your candidates’ technical skills, in whatever language, sign up for our free demo.