Your IDE, its refactoring tools, but especially its debugger.
VSCode or PyCharm (assuming you are still a Python developer) could be a good place to start. I'm always surprised when I see professional developers coding in Sublime Text and debugging with print statements (or their equivalent). Usually you have better options than that, especially for statically-typed languages - but even for JS and Python.
VSCode or PyCharm (assuming you are still a Python developer) could be a good place to start. I'm always surprised when I see professional developers coding in Sublime Text and debugging with print statements (or their equivalent). Usually you have better options than that, especially for statically-typed languages - but even for JS and Python.