C++ Developer

Persistent Systems; Pune District; On-site; INR 2,800,000 - 4,200,000; Full time

Benefits offered by this job

Hybrid work

Flexible hours

Higher education sponsorship

Long service awards

Insurance coverage

Job summary

Persistent Systems in Pune is seeking a Telecom C++ Developer with deep expertise in 4G/5G protocol parsing and state machines. You will work on live signaling traffic, build high-performance parsers, and help deliver analytics across LTE and 5G cores.

The role requires 8–12 years in telecom software, strong C++17+, Linux, Docker, and Kubernetes experience, and collaboration with cross-functional teams to drive end-to-end protocol solutions.

Qualifications

• 8–12 years of experience in telecom software development, mobile core networks, or protocol engineering.
• Strong hands-on expertise in modern C++ (C++17 or later) and systems programming.
• Experience with 4G/5G signaling protocols (S1AP, NGAP, GTP-C, PFCP, NAS, 5G SBA).

Responsibilities

• Design and develop 4G protocol parsers and state machines for S1AP, GTP-C, PFCP, SGsAP.
• Design and develop 5G protocol parsers and state machines for NGAP interfaces.
• Implement multi-protocol correlation engines to track subscriber and session lifecycles.
• Correlate S1AP/NGAP contexts with GTP-C, PFCP, NAS, and SBI service interactions.
• Develop unit and integration tests using PCAP traffic replay environments.
• Collaborate with packet ingestion teams on ZMQ interfaces and packet metadata design.
• Contribute to Docker packaging, Helm charts, and Kubernetes deployments.

Skills

Modern C++

Multithreading

High-performance apps

Linux

Docker

Kubernetes

GIT/CI/CD

Tools

Docker

Kubernetes

Git

Job description

We are looking for an C++ Developer with strong 4G and 5G protocol expertise to join the team responsible for real-time parsing, decoding, and state tracking of mobile core network signaling. The role involves developing protocol parsers and state machines that process live LTE and 5G control-plane traffic, extract structured events and session records, and provide downstream analytics. The ideal candidate will have deep expertise in 3GPP standards, LTE EPC, 5G Core SBA, and high-performance C++.

• Role: Telecom C++ Developer
• Location: Pune
• Experience: 8 to 12 years
• Job Type: Full-Time Employment

What You'll Do:

• Design and develop 4G protocol parsers and state machines for S1AP, GTP-C v1/v2, PFCP, and SGsAP.
• Design and develop 5G protocol parsers and state machines for NGAP and Service-Based Architecture (SBI) interfaces.
• Implement multi-protocol correlation engines to track complete subscriber and session lifecycles.
• Correlate S1AP/NGAP contexts with GTP-C, PFCP, NAS, charging, and SBI service interactions.
• Build protocol decoding frameworks aligned with evolving 3GPP releases.
• Analyze and process LTE and 5G network signaling for registration, mobility, charging, authentication, roaming, and policy control use cases.
• Develop unit and integration test frameworks using PCAP-based traffic replay environments.
• Collaborate with packet ingestion teams on ZMQ messaging interfaces and packet metadata design.
• Contribute to Docker packaging, Helm chart development, and Kubernetes deployments.
• Participate in architecture reviews, code reviews, troubleshooting, and technical documentation.

Expertise You'll Bring:

• 7 to 12 years of experience in Telecom Software Development, Mobile Core Networks, Network Analytics, or Protocol Engineering.
• Strong hands-on expertise in Modern C++ (C++17 or later), systems programming, multithreading, memory optimization, and high-performance applications.
• Deep understanding of LTE EPC and 5G Core network architecture.
• Extensive experience with S1AP, NGAP, NAS, GTP-C, PFCP, Diameter, SGsAP, and 5G Service-Based Interfaces.
• Strong understanding of LTE Attach/Detach, EMM/ESM procedures, Bearer Management, and HSS integrations.
• Experience with 5G Registration, Deregistration, PDU Session Management, Nudm, Nausf, Namf, and Nsmf services.
• Expertise in LTE and 5G mobility management including S1, X2, Xn, N2, Inter-RAT, N26, and N3IWF handovers.
• Strong knowledge of 4G and 5G authentication frameworks including LTE AKA, 5G AKA, EAP-AKA, SUCI/SUPI, AUSF, UDM, SEAF, and ARPF.
• Experience implementing Security Mode procedures, NAS security, and access security activation.
• Hands-on experience with telecom charging and policy platforms including Gy, Gz, Gx, PCRF, CHF, PCF, and QoS Policy Management.
• Strong understanding of LTE and 5G roaming architectures including S8/S9, SEPP, N32, Local Breakout, Home Routed Roaming, and Inter-PLMN signaling.
• Experience with paging procedures, idle mode mobility management, UE reachability services, and event exposure mechanisms.
• Knowledge of IMS, VoLTE, VoNR, voice services, and telecom service interaction frameworks.
• Hands-on experience with Wireshark, PCAP analysis, protocol troubleshooting, telecom probes, and signaling analysis tools.
• Experience with Linux, Docker, Kubernetes, Helm, Git, CI/CD pipelines, and cloud-native deployments.
• Exposure to ZeroMQ messaging frameworks and distributed event-processing architectures.
• Strong analytical, debugging, troubleshooting, and communication skills with the ability to model complex telecom procedures into scalable protocol state machines and analytics engines.
• Competitive salary and benefits package
• Culture focused on talent development with quarterly growth opportunities and company-sponsored higher education and certifications
• Opportunity to work with cutting-edge technologies
• Employee engagement initiatives such as project parties, flexible work hours, and Long Service awards
• Insurance coverage: group term life, personal accident, and Mediclaim hospitalization for self, spouse, two children, and parents

Values-Driven, People-Centric & Inclusive Work Environment:

Persistent is dedicated to fostering diversity and inclusion in the workplace. We invite applications from all qualified individuals, including those with disabilities, and regardless of gender or gender preference. We welcome diverse candidates from all backgrounds.

• We support hybrid work and flexible hours to fit diverse lifestyles.
• Our office is accessibility-friendly, with ergonomic setups and assistive technologies to support employees with physical disabilities.
• If you are a person with disabilities and have specific requirements, please inform us during the application process or at any time during your employment

Let's unleash your full potential at Persistent - persistent.com/careers

"Persistent is an Equal Opportunity Employer and prohibits discrimination and harassment of any kind."