Sr. Software Development Engineer - Network, Security, LLM

About Zscaler

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.

• 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.

• You thrive in ambiguity. You’re comfortable building the path as you walk it. You thrive in a dynamic environment, seeing ambiguity not as a hindrance, but as the raw material to build something meaningful.
• You act like an owner. Your passion for the mission fuels your bias for action. You operate with integrity because you genuinely care about the outcome. True ownership involves leveraging dynamic range: the ability to navigate seamlessly between high‑level strategy and hands‑on execution.
• You are a problem‑solver. You love running towards the challenges because you are laser‑focused on finding the solution, knowing that solving the hard problems delivers the biggest impact.
• You are a high‑trust collaborator. You are ambitious for the team, not just yourself. You embrace our challenge culture by giving and receiving ongoing feedback—knowing that candor delivered with clarity and respect is the truest form of teamwork and the fastest way to earn trust.
• You are a learner. You have a true growth mindset and are obsessed with your own development, actively seeking feedback to become a better partner and a stronger teammate. You love what you do and you do it with purpose.

• 8+ years of software engineering experience
• Deep experience in systems programming using Rust, with a focus on asynchronous frameworks such…