Which companies or large projects use TDD at the moment? There's always such intense discussion about what it is and its benefits, yet I don't see anyone actually doing TDD.
I've been in several multi-million line codebases that all were built with TDD. It's possible.
The default way of organizing code with DI makes unit tests extremely expensive to write and maintain. Mocks should be banned if you want to add unit tests or practice TDD. Instead the tested code should be pure. Pure code is easy to test, even if it's calling a dozen helper functions.
Dozen-ish person team, 3 year project so far, billion dollar revenue company (not a software company), >500k LOC, TDD since the beginning. Have been doing TDD for 18 years or so. Still getting better at it.
