It sounds like you are struggling with two different things. Problem 1: Your manager isn't giving you the space to diagnose and fix the issue. The solution to

It sounds like you are struggling with two different things. Problem 1: Your manager isn't giving you the space to diagnose and fix the issue. The solution to this is to explain to them the situation in as much detail as it takes why you need a certain amount of time. If they don't want to listen then it's time to start looking for different employment. It's a great time to be looking, seriously, the market is crazy hot right now. Problem 2: You are using abstractions that hide details you need to understand when things go wrong. The solution here is to go read the code, write small examples that trigger replicate the problem. Use a debugger. Get really familiar with the code in the abstraction you are using. The answer is in there somewhere and more than likely you can figure it out if you trace through. It's a partial failure of our industry that many times these abstractions make it really difficult to figure out why they went wrong. But it's our reality and sometimes it takes weeks of reading the code and experiementing to identify why it's breaking. The good news is that once you've done that you are just a little bit more of an expert in that abstraction, and that is a very marketable skill.