Principal Software Development Engineer (Backend Dev - C/Linux/GDB)

Zscaler (NASDAQ: ZS) accelerates digital transformation so customers can be more agile, efficient, resilient, and secure. The Zscaler Zero Trust Exchange platform protects thousands of customers from cyberattacks and data loss by securely connecting users, devices, and applications in any location. Distributed across 200+ public data centers globally and thousands of private sites at the edge, the SASE-based Zero Trust Exchange is the world’s largest in-line cloud security platform. We believe the future of work is Human + AI and are building an AI-native enterprise where human potential is amplified by machine intelligence to solve the world’s hardest security challenges. Driven by deep customer obsession, we are committed to the mission, outcome, and to each other. We bring these commitments to life through three core behaviors: ownership and collaboration, trust through outcomes and impact, and a challenge culture with ongoing feedback. Ready to make an impact at the company pioneering security transformation in the AI era? Join us at Zscaler. Role We are looking for a Principal Software Development Engineer to join our team. This is a Hybrid role, reporting to the Senior Manager, Software Development Engineering in the Data Protection department. In this position, you will serve as a premier technical leader, defining architectural direction, designing high-performance systems-level subsystems, and driving the engineering execution of our next-generation inspection capabilities. What you’ll do (Role Expectations) • Architect and implement high-performance DLP engines, dictionary compilers, and distributed incident processing pipelines, setting the benchmark for clean, highly optimized systems-level C code running in production proxy runtimes • Own the technical direction and architectural roadmap for line-rate pattern matching, regular expression evaluators, custom dictionary compilers, exact data match (EDM), and indexed document matching (IDM) • Help develop next-generation Data Loss Prevention (DLP) solutions utilizing Machine Learning (ML) models, collaborating with data science teams to successfully deploy and integrate models in high-throughput data paths while balancing inspection capabilities against strict network latency and resource constraints • Establish and enforce exacting architectural standards for multi-threaded C daemons on FreeBSD/Linux, designing robust shared memory structures, high-performance Inter-Process Communication (IPC), lockless concurrency, and memory-safe subsystems • Serve as the technical escalation authority for critical production issues—leading hands-on post-mortem core dump analysis, deep system profiling, and leak detection Who You Are (Success Profile) • You act like an owner with a bias for action, navigating seamlessly between high-level architectural strategy and hands-on execution. • You are a high-trust collaborator who embraces open feedback, communicates with candor and respect, and champions the collective success of the engineering team. • You are customer-obsessed, anchoring technical and design decisions in solving real-world challenges for both internal stakeholders and external users. • You are driven by innovation and intellectual curiosity, continually seeking robust, secure, and scalable approaches to complex systems engineering challenges. • You lead with integrity and high accountability, building trust through consistent, transparent action and technical stewardship. What We’re Looking for (Minimum Qualifications) • Foundational understanding of AI/ML technologies and experience leveraging, securing, or positioning AI-driven solutions to optimize outcomes within your functional domain • 10+ years of experience with systems software engineering, incl