Sr. Staff Software Development Engineer - Network, Security, LLM

Zscaler•San Jose, CA

3h•Hybrid

About The Position

Zscaler is a pioneer and global leader in zero trust security. The world’s largest businesses, critical infrastructure organizations, and government agencies rely on Zscaler to secure users, branches, applications, data & devices, and to accelerate digital transformation initiatives. Distributed across more than 160 data centers globally, the Zscaler Zero Trust Exchange platform combined with advanced AI combats billions of cyber threats and policy violations every day and unlocks productivity gains for modern enterprises by reducing costs and complexity. Here, impact in your role matters more than title and trust is built on results. We believe in transparency and value constructive, honest debate—we’re focused on getting to the best ideas, faster. We build high-performing teams that can make an impact quickly and with high quality. To do this, we are building a culture of execution centered on customer obsession, collaboration, ownership and accountability. We champion an “AI Forward, People First” philosophy to help us accelerate and innovate, empowering our people to embrace their potential. If you’re driven by purpose, thrive on solving complex challenges and want to make a positive difference on a global scale, we invite you to bring your talents to Zscaler to help shape the future of cybersecurity. We are looking for a Senior Staff Software Development Engineer to join us as a founding member of our AI Security Team. This is a hybrid role for San Jose, CA, reporting to the Director of Software Engineering within the Emerging Tech org. You will be responsible for designing and implementing core infrastructure components and distributed systems, serving as a foundational architect for our AI security solution. This high-impact role focuses on scaling security infrastructure to support hundreds of millions of users, collaborating with stakeholders across the development lifecycle to drive innovation and technical excellence.

Requirements

Deep experience in systems programming using Rust, with a focus on asynchronous frameworks such as Tokio or async-std
Proven ability to design and implement horizontally scalable, highly available, and observable distributed systems
Strong command of Linux internals, including kernel-user space interaction, networking, sockets, and namespaces
Skilled in performance instrumentation, containerized environments, Git workflows, and CI/CD pipelines

Nice To Haves

Expert in systems languages such as C/C++ or Rust, with a focus on performance optimization
Deep understanding of Linux networking stacks, Kubernetes networking, service meshes, and LLM model optimization
Practical experience with gRPC, Protobufs, and L4-L7 networking protocols, including TCP/IP, TLS, QUIC, HTTP, and WebSockets (WSS)

Responsibilities

Architect, develop, and optimize a low-latency, high-throughput AI Security plane utilizing Rust, specifically leveraging its async/await model for highly efficient I/O and service-oriented architecture
Build resilient, distributed, and scalable systems, emphasizing concurrency, fault tolerance, and robust messaging protocols
Implement and maintain gRPC services and APIs to ensure seamless integration of the AI Security plane with control and orchestration infrastructure
Systematically enhance performance across the entire stack, including LLM models, by employing profiling tools for both kernel-space and user-space components
Lead complex, multi-functional projects and initiatives, defining the technical roadmap and driving execution across teams