Tell me about one task you are most proud of or that caused the greatest difficulties.

One of the tasks I am proud of is related to optimizing the performance of a large Java application working with big data.

The problem was that during peak loads, the application slowed down significantly due to inefficient thread management and frequent blocking.

I conducted an analysis using a profiler, identified bottlenecks in synchronization, and redesigned the multithreading architecture by replacing locks with lighter constructs such as ConcurrentHashMap and Atomic variables. I also implemented a thread pool with dynamic size management.

As a result, I was able to increase performance by 40%, reduce response time, and improve system stability under load.