The Bug Wasn't in Java

As developers, when something goes wrong, the first thing we usually do is look at our own code. I do the same. But there are some bugs where you can read your Java code over and over and still never find the answer there.

A database connection issue, a Docker image problem, an environment variable, a character encoding mismatch, a network timeout, or a response from some other service — any of these can masquerade as a Java exception for hours. In reality, the application itself has nothing wrong with it.

A stack trace doesn't tell you everything

Seeing an exception isn't the same as finding its cause. A stack trace shows me where the problem surfaced. Finding the actual reason behind it is a separate job.

For example, an issue coming from the database can show up as an exception at the application layer. A problem in the connection pool might only appear when a repository call is made. A network glitch can end up disguised as an exception thrown by FeignClient.

That's why lately, during debugging, I try to ask less "where did this error occur?" and more "which layers of the system did this error pass through before it reached here?"

Debugging is engineering too

I don't think being a good developer is measured only by how many new features you ship. Calmly investigating what's actually happening in an existing system is just as much a part of the job.

Sometimes the best solution isn't writing more code. It's proving where the problem isn't.

You can find more of my writing here:
https://aladdinbiyabangerd.site/en/writing