OnlineSales.ai Interview Experience for Java Backend Developer

I recently had an interview through Naukri.com, but unfortunately, I didn’t make it past the initial round. Here’s a breakdown of the questions I faced and where I think I could improve:

1. Processes vs. Threads (Memory-wise):
   • Processes are like separate tasks with their own memory space, while threads are lighter versions that share memory within a process.
2. HTTP vs. HTTPS and OSI Layer:
   • HTTP is like sending web data without security, and it works at the application layer (like a user interface). HTTPS adds security through encryption and operates at a deeper level (like a security layer).
3. Finding the Odd Element in an Array:
   • I had to find a single number in an array where everything else appeared twice. It’s tricky but usually solved with smart algorithms.
4. SQL Query for Finding Highest Salary per Department (Optimized):
   • This task involved writing a SQL query to efficiently find the highest salary in each department using techniques to minimize processing time.
5. SQL Query for Finding Second-Largest Salary (Optimized):
   • Similarly, I had to craft a SQL query to find the second-largest salary using efficient methods to avoid unnecessary computation.

Though I didn’t succeed this time, I see it as a chance to improve my skills for future opportunities.