An SDET is a developer and not a tester

Photo by Markus Spiske on Unsplash

More and more companies require that both the application code and the test automation code (for UI, API, etc) are written in the same language. This can be Java, C#, JavaScript, Python or Ruby.

The reason is simple.

They want the developers to contribute to the test automation code, read it and maintain it (if needed).