Share your experience of situations where something went wrong and how you handled the situation.

Once, while working on a Java project, I encountered a situation where the application suddenly started to slow down significantly when processing large volumes of data. After analyzing logs and profiling memory, I found that the problem was related to a memory leak caused by improper use of collections — objects were not being released, and the garbage collector couldn't clean them up.

To solve the problem, I:

• Rewrote the code, replacing ArrayList with LinkedList in places where elements were frequently removed, which improved performance.
• Introduced explicit nullification of references to objects that were no longer needed.
• Added memory profiling using VisualVM for real-time monitoring.

As a result, the application became stable and fast, and I gained valuable experience in memory optimization and profiling Java applications.