[throwaway4302]

Depends on the situation

Work:

I prefer tech that is well known within the team that will maintain it. Keep the bus factor low.

Personal side projects:

It depends on my goal. Is the goal to learn a specific tech, or create a product? If my goal is a product, I choose tech that I know well. I want to focus on the product, and not spend time in google/chatgpt figuring out how to do X in Y. The product itself has so many unknowns, that I don't want to add more due to my choice of tech, otherwise I risk losing my motivation and the project ends up in limbo.

If I had to choose a single language for everything, it would be Java (or Kotlin if necessary). The eco system is solid and my productivity is easily 4x compared to other languages.

Most developers can learn to produce code in any language in days. But mastering a language and eco system takes years.