Senior Sustaining Software Engineer

Job Summary

We are looking for a Senior SD-WAN Sustaining Engineer to develop, troubleshoot, and debug software for an SD-WAN appliance/platform. The role focuses primarily on production support, sustaining engineering, complex defect resolution, and product reliability rather than new feature development.

The ideal candidate should have strong C/C++, Linux, networking, and SD-WAN experience, with excellent debugging and root-cause analysis skills.

Key Responsibilities

• Investigate and resolve complex production and customer issues in SD-WAN software.
  
• Perform root-cause analysis across datapath, routing, packet processing, session management, and system components.
  
• Develop, test, and deliver high-quality fixes for supported releases.
  
• Debug issues related to performance, scale, HA, configuration, networking, and hardware/OS interactions.
  
• Work closely with Engineering, QA, Product Management, and Release Engineering teams.
  
• Improve product reliability, supportability, logging, diagnostics, and troubleshooting capabilities.
  
• Develop unit, integration, functional, and regression tests to prevent recurring issues.
  
• Participate in code reviews with focus on performance, compatibility, concurrency, security, and regression risks.
  
• Analyze recurring defects and field issues and drive long-term corrective actions.
  
• Support release readiness, maintenance releases, defect reviews, and technical documentation.
  
• Clearly document root cause, resolution, testing, and customer/product impact.
  

Required Skills

• 6-10 years of software engineering experience, preferably in networking, security, distributed systems, or telecom products.
  
• Strong C and/or C++ programming experience.
  
• Strong Linux systems and debugging skills.
  
• Good understanding of IPv4/IPv6, TCP/UDP, routing, forwarding, tunneling, NAT, QoS, and packet flows.
  
• Hands-on experience with SD-WAN, routers, firewalls, network operating systems, or networking products.
  
• Experience with GDB, packet capture tools (Wireshark/tcpdump), logs, tracing, and performance analysis tools.
  
• Strong experience in troubleshooting production, intermittent, performance, scale, and environment-specific issues.
  
• Ability to trace issues across control plane, management plane, and datapath.
  
• Experience with Git/source control, code reviews, CI/CD, defect tracking, and regression testing.
  
• Strong analytical, problem-solving, communication, and ownership skills.
  
• Bachelor's or Master's degree in Computer Science, Computer Engineering, Electrical Engineering, or equivalent practical experience.
  

Good to Have

• Experience developing or sustaining SD-WAN appliances.
  
• Experience with networking/security products or carrier-grade systems.
  
• Knowledge of high availability, packet processing, performance optimization, and system-level troubleshooting.
  
• Experience working on maintained release branches and backporting production fixes