If your mistakes are only pushing things back a month, that's really not bad at all. Especially since you're new. Once you're more experienced, and working on

If your mistakes are only pushing things back a month, that's really not bad at all. Especially since you're new. Once you're more experienced, and working on bigger things, then your mistakes will push things back a whole quarter. It happens. That's just part of it. We all make mistakes and bork things, and it has effects like that sometimes. Just learn from it and try to do well enough in the times you don't make mistakes that overall it's a net positive. As to the rest - not knowing the process, and apparently your team also not knowing the process - indicates that the process isn't clear. You don't have checklists in place, or the relevant review steps or whatever. That's not your fault. You might do well to advocate for a little more formalization there. But try not to go overboard. As a new person, it's a difficult situation. But raising the concern might open some people's eyes and shine a light on problems they'd been conveniently pushing off. Your work (everyone's work) should go through a testing and review process involving multiple people. As in, you test yourself, someone else reviews your work, then someone else tests it, and finally someone else (often a non-developer subject matter expert) confirms that the work and testing done meet the intended objectives. The end result should be a documented checklist. Multiple people, from different viewpoints, have said this is good to go. Then mistakes aren't all yours (or your coworker's), they're a case where the entire team and process failed, and the solution is to fix the process so that doesn't happen again. You (and everyone else) will still make mistakes, of course, we all do, but it doesn't have as much of an impact if the process catches it.