Tell us about the last task you successfully completed and describe your approach to it.

Recently, I was solving a performance optimization problem for a Java application that processed large volumes of data and was slow.

Approach:

1. Conducted profiling using VisualVM to identify bottlenecks.
2. Discovered that a significant amount of time was spent on frequent creation and destruction of objects.
3. Rewrote part of the code using an object pool and reuse to reduce the load on the garbage collector.
4. Optimized sorting and filtering algorithms by replacing them with more efficient data structures (e.g., LinkedList to ArrayList).
5. Added multithreading using ExecutorService for parallel data processing.

As a result, processing time was reduced by about 3 times, and the application became more responsive and stable.