Progress Software Engineer II interview questions

I am a Software Engineer with an experience of 4 years in C++ development when appearing for the interview with Progress. The interview stared with a small introduction followed by some question related to the work updated on resume. Questions were asked on: 1. Socket Programming explanation to a newbie. 2. Multi-threading with synchronization mechanism- Mutex, Semaphore and Critical Section 3. Basic OOPS Concepts 4. DS Questions mentioned below

Round 1 - F2F Round 2 - Online coding Round 3 - Onsite Interview Round 4 - Manager Round Questions are based on DS and Ruby Should have strong knowledge in Data structure and algorithms