CodeSignal’s advanced coding environment supports over 70+ coding languages, frameworks, and libraries. In addition to the standard single-file interview coding challenges, we support filesystem-enabled coding challenges that simulate the real development environment. You can assess a variety of roles using CodeSignal such as full-stack, backend, frontend, DevOps, mobile, data scientist, and more. Here is the full list of languages and related libraries we support. Coding Languages & Libraries: We support a large selection of coding languages, including the widely used ones: Java, JavaScript, Python, PHP, React, Ruby, Swift, and more. Unit Test Frameworks: CodeSignal’s state-of-the-art IDE supports a number of unit test frameworks. Some examples include: NUnit for .NET Framework xUnit or NUnit for .NET Core JUnit for Java Mocha/Chai for JavaScript PHPUnit for PHP unittest for Python RSpec for Ruby UI tests using Galen UI functionality tests using Puppeteer