Persistent Systems — Senior Telecom Software Developer Interview Experience

Persistent Systems — Senior Telecom Software Developer Interview Experience

Role: Senior Telecom Software Developer
Company: Persistent Systems
Mode: Online interview via TalView
Date: 16 September 2026
Experience level: ~3 years C++/Linux/5G Core

I recently interviewed for a Senior Telecom Software Developer role at Persistent Systems.

The role/JD was focused heavily on C/Linux and telecom networking, including LTE/5G RAN architecture, NAS, SCTP, NGAP, S1AP, X2/X2AP, RRC, GTP, eNodeB/gNodeB, protocol troubleshooting, debugging, integration testing and performance optimization.

I spent most of the time for preparing alll the topics in JD, c++ fundamentals revision, OS fundamnetals.

The interview was not exactly the same as the preparation emphasis.

One of the coding questions was:

Write a program to reverse a string.

I wrote the solution in C++, and the code worked.

The interviewer then asked me to write it in C. I forgot some syntax of C felt like he was not satisfied with that and most of the time he grilled me on C keywords like volatile, extern , const, static, I answered some of them, so finally if you have this interview in coming days i suggest you to go through C syntax and keywords in depth reather then studying about networking,linux/OS fundamentals.