A Tale of Inter‑Service Bugs and Exception Handling in Backend Development

Yesterday I saw a story on a social platform that, for the sake of discussion, we’ll assume is true.

Zhang and Wang are two backend developers at a company, each responsible for the development of systems A and B respectively – this is the background.

In a certain interface business scenario, the client calls system A’s interface, and during processing, system A calls system B’s interface.

During routine feature development, Wang (responsible for system B) often receives bug reports from testers that initially point to the responsible party, but after investigation many issues are not caused by the B service; they are due to missing validation and exception handling in the A service.

Before a recent project summary meeting, Wang carefully compiled the bugs under his responsibility, focusing on their final outcomes and flow.

He discovered that a significant portion of the bugs were actually terminated in Zhang’s system, and the problematic modules were relatively concentrated, which sparked Wang’s curiosity. After tracing the root cause, he uncovered a shocking hidden agenda.

The pseudo‑code illustrating the issue is as follows:

try {<br/>    // ... five hundred lines of code omitted<br/>    callBSystemMethod(params);<br/>    // ... another five hundred lines omitted<br/>} catch (Exception e) {<br/>    logger.warn("系统异常!", e);<br/>    return Result.fail("B系统调用异常!");<br/>}

Haha…

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