Have you communicated to the boss in a rational way that this is such a big deal to you it would cause you to leave? Or have you just told them the other guy is

Have you communicated to the boss in a rational way that this is such a big deal to you it would cause you to leave? Or have you just told them the other guy isn't good. This is how I typically approach these types of problems.... Ask yourself if you're ready to see this through and by that I mean every possible outcome including leaving or getting fired or potentially getting the other guy fired. That means assessing your financial situation, possibility of getting more work etc. to me the logic goes that if this is such an important thing then I should be willing to accept all outcomes as this is the Right Thing To Do. It might seem a little melodramatic but it forces you to ask yourself hard questions. Then, approach the boss. Tell him that you heard what he said before but the quality of your colleagues work is such that you can't stand over it and it's affecting everyone working on the project. If you end up having double standards for the code it brings everything down to the lowest common denominator. My next option would be to bring a _solution_ to the table as opposed to just a problem. Let's bring in code reviews and I'll work with MrProblemCoder directly on his reviews one on one for a few months to try and bring his standard up. However, you need management backup for this. Maybe you don't even want to single him out, maybe you sit down collectively once or twice a week to do group reviews and breakouts afterwards. Maybe Friday afternoons are review the review days. The big thing here is that you want to make clear to the boss that there is a Significant Problem in a clear, rational way and have him understand the impact of it. Try leave your emotion at the door. Then present a solution which involves the group taking collective responsibility for the code quality with you leading the charge, but that management must back up and present. If the outcome of that conversation isn't positive, then you have a management who doesn't care about quality and more importantly doesn't trust what you're saying about the impact. That would make it much easier for me to walk away as I now understand they've chosen the next path for themselves. If you're not ok with that path then you could still try "influencing" these types of initiatives over a longer period of time instead of entering in to brinksmanship. Institutionalise code reviews for a portion of the team and show less bugs/rework and show the cost of crappy code. It's a softer approach and may take months and months of collecting data and influencing your colleagues. These situations are not easy unless you're actually in a position to institute change directly!