Break-point debuggers take too long in most environments (with a few exceptions). I use linters, compilers and type checkers as my first line of defense. Next, logging and unit tests. Lastly, I like to have in interactive command line REPL with good tab completion if one is available and not to difficult to setup.

In python, for example I use: pycodestyle, pyflakes, mypy and logging, and bpython.

For web apps, reload time is the most important factor. Work on reducing the time to compile, reload and test.