You need to make a choice: 1. Try to get the political will to change it, then lead a change. This is essentially impossible unless you're a respected senior d

You need to make a choice: 1. Try to get the political will to change it, then lead a change. This is essentially impossible unless you're a respected senior developer, and even there it is hard. There is a lot of advice out there, but the primary thing I've seen work is this: Complete feature freeze. API-ify the backend with heavy tests through the API. Have the presentation layer slowly shift to the new API. Once the API is complete, delete all the other backend code. Refactor the presentation layer with tests as you go. 2. Accept that the codebase is shit and look at your situation realistically. If you can't switch jobs (visa issues, etc) you need to accept that this is the way it is at this company and don't grumble about it. Spend 20% of your time making tools that help you compensate for the shit quality of the codebase; admittedly this is easier on non-Windows projects. Even so, making a small tools for disorganized projects really helps make you look super pro, even if the code is doing most of the work. 3. Quit and work somewhere else with better people and a better codebase. Out of all the reasons I advocate TDD, from cybersecurity to QA, they pale in comparison to employee retention. Keeping a codebase clean over time requires tests. It just does. If you don't have tests things ossify. I don't write tests for ad-hoc querying data, but I always write them for long lived projects and I refuse to work on established projects that don't have test suites (or direction from on-high to add them).