Persistent Systems — Senior Telecom Software Developer Interview Experience
Summary
I interviewed for a Senior Telecom Software Developer role at Persistent Systems; the interview emphasized C/C++ fundamentals and networking, and I struggled with C syntax and keywords.
Full 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.
Interview Questions (1)
Reverse a String
Write a program to reverse a string.
Preparation Tips
I spent most of my preparation time reviewing the job description topics, revising C++ fundamentals, and studying OS fundamentals. Based on the interview, I would also focus on C syntax and keywords such as volatile, extern, const, and static.