The interview process was well-structured and professional. It started with an initial HR screening call that focused on background, experience, and motivation.

The technical stage included one to two coding interviews covering:

• Data structures
• Algorithms
• Problem-solving

Questions required writing clean, efficient code and explaining trade-offs. There were also discussions around system design and past project experience.

In addition, the interviewers asked in-depth questions about core concepts relevant to the role (e.g., multithreading, OOP principles, memory management, or performance optimization).

Given an array of integers, return the length of the longest strictly increasing subsequence.

Explain your approach, analyze time and space complexity, and discuss possible optimizations.