Welcome to software engineering, this is how things are here. It is very unlikely that you will ever work on a large project that gives you a warm feeling in yo

Welcome to software engineering, this is how things are here. It is very unlikely that you will ever work on a large project that gives you a warm feeling in your belly. So learn to grow on it. Rewriting random code as a codebase newbie is always a mistake. You will get things wrong. Mistakes can be delayed a long time before you are aware of it. Try to understand the product. You should spend more time to understand the product features and flow instead of staring at single ugly code fragments. Understanding it will reveal some structure in the code, even if it isn't explicit. Try to engage your peers about things you don't understand. They will potentially deliver tons of detail and background information. Over time you can mentally map this high level information to the codebase. If you understand the product better, I'd suggest to write a few (1-5) simple selenium tests that cover the core tasks of the product. This test is simply to ensure that you do not break something on the greater scale and the product is still delivering it's basic value. If you start to find confidence with you tests, you can share them with your peers. This will give everyone some instant value and potentially a lot of respect towards you. You seem to be afraid of your colleague. You don't even know if he wrote all that code, you don't know about his stance on the codebase. Engage him, try to find out how he is working with the codebase. Try to find out his skill level and mentality. Do not judge early, don't complain. Even if he is low skilled, he could have a lot of knowledge about the product and the company. Eventually don't expect to rewrite the whole codebase. Rewriting a large valuable project which is in production will take easily a year. One year after that someone will claim this is legacy. It won't help. It is easy to think that you can do better, but even a clean codebase can be a huge mess. Figure out how to gradually improve the project alongside features. Figure out risks and high friction tasks for devs, operations and users.