Others have offered good advise so far, so let me try to not sound too redundant. The first and foremost thing you must understand is that each code base has a

Others have offered good advise so far, so let me try to not sound too redundant. The first and foremost thing you must understand is that each code base has a personality of its own. Code bases, like people, change over time but they rarely deviate from their core character. And the more money that code is making for someone, the more resistant it grows to change. So, the thing is, don't put so much of your identity on it. It is not personal and it is not about you. In due time you will have chances to try your hand and build something from scratch, but until that day comes you need to work with other people's code in order to learn what approaches are feasible and where the pitfalls are. In this particular case, only you can decide if the current code base is so much of a mess for you to bother. But you owe to yourself to give it another try, this time from the perspective that you want to make it not perfect, but as good as it can be. Once you have given an honest try to assess the potential of this system, and can explain in detail why that is negligible or non existent, you may look for the next job with a clean conscience.