Fair enough, and I have had similar experiences. I would note a few things: - Sounds like a major undertaking. - You note this was done in service of refacto

Fair enough, and I have had similar experiences. I would note a few things: - Sounds like a major undertaking. - You note this was done in service of refactoring. So you didn't test yourself out of the mess so much as use testing to enable the simplification that got you out of the mess. - I would argue that what is really happening here is that, by spending the time to create these tests and refactor, the current team is creating a shared mental model of the messy codebase -- they are making it understandable, at least in large part. So, you might amend my original statement "there is not substitute for simplification and good design" to "there is not substitute for making the code comprehensible". While a simple, good design is the best way to do this... it can also be achieved by having everyone expend more effort to understand a bad design well enough to work with it. And this latter strategy is, in practice, the far more common one.