Principal Software Development Engineer - Rust, LLM, Networking

About Zscaler

Zscaler accelerates digital transformation to ensure our customers can be more agile, efficient, resilient, and secure. As an AI-forward enterprise , we are constantly pushing the envelope, leveraging the world’s largest security data lake to power our cloud-native Zero Trust Exchange platform. This innovation protects our customers from cyberattacks and data loss by securely connecting users, devices, and applications in any location.

Here, impact in your role matters more than title and trust is built on results. We say, impact over activity. We seek innovators who actively use AI to amplify their impact and who thrive in an environment where we leverage intelligent systems to stay ahead of evolving threats. 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 value high-impact, high-accountability with a sense of urgency where you’re enabled to do your best work and embrace your potential. If you’re driven by purpose, thrive on solving complex challenges, and want to be part of the team that’s helping to secure the AI age, we invite you to bring your talents to Zscaler and help shape the future of cybersecurity.

Role

We are hiring a Principal Software Development Engineer to be a founding member of our AI Security Team, offering the chance to build a high-reliability, low-latency AI security solution designed to scale for hundreds of millions of users. In this role, reporting to the Director, Software Development Engineering, you will be responsible for designing and implementing core infrastructure components and distributed systems while collaborating closely with various stakeholders throughout the development lifecycle. This is a hybrid role, reporting in to the San Jose, CA office 3 days a week.

What you’ll do (Role Expectations)

• 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.

• Contribute actively to the team through technical documentation, system design reviews, code reviews, and by mentoring junior engineering staff.Lead complex, multi-functional projects and initiatives, defining the technical roadmap and driving execution across teams.

Who You Are (Success Profile)

• Drive the mission with an owner's mindset, seamlessly bridging high-level strategy and detailed, hands-on execution.

• Actively seek challenges and find complex solutions that deliver maximum impact.

• Deeply empathize with internal and external stakeholders, anchoring every decision in addressing their real-world problems.

• Maintain strong technical curiosity, continually seeking more secure, scalable, and effective methods to accelerate transformation.

• Connect your work to the company's broader mission, designing solutions to support high-growth, global organizational needs.

What We’re Looking for (Minimum Qualifications)

• 12+ years of software engineering experience

• 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.

What Will Make You Stand Out (Preferred Qualifications)

• 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, and WebSockets (WSS).

• Direct experience in validating AI-driven products, including understanding of model performance metrics and MLOps principles.

#LI-BH1

#LI-Hybrid

Zscaler’s salary ranges are benchmarked and are determined by role and level. The range displayed on each job posting reflects the minimum and maximum target for new hire salaries for the position across all US locations and could be higher or lower based on a multitude of factors, including job-related skills, experience, and relevant education or training.

The base salary range listed for this full-time position excludes commission/ bonus/ equity (if applicable) + benefits.

Base Pay Range

$182,000—$260,000 USD

At Zscaler, we are committed to building a team that reflects the communities we serve and the customers we work with. We foster an inclusive environment that values all backgrounds and perspectives, emphasizing collaboration and belonging. Join us in our mission to make doing business seamless and secure.

Our Benefits program is one of the most important ways we support our employees. Zscaler proudly offers comprehensive and inclusive benefits to meet the diverse needs of our employees and their families throughout their life stages, including:

• Various health plans

• Time off plans for vacation and sick time

• Parental leave options

• Retirement options

• Education reimbursement

• In-office perks, and more!

Learn more about Zscaler’s Future of Work strategy, hybrid working model, and benefits here ( .

By applying for this role, you adhere to applicable laws, regulations, and Zscaler policies, including those related to security and privacy standards and guidelines.

Zscaler is committed to providing equal employment opportunities to all individuals. We strive to create a workplace where employees are treated with respect and have the chance to succeed. All qualified applicants will be considered for employment without regard to race, color, religion, sex (including pregnancy or related medical conditions), age, national origin, sexual orientation, gender identity or expression, genetic information, disability status, protected veteran status, or any other characteristic protected by federal, state, or local laws. See more information by clicking on the Know Your Rights: Workplace Discrimination is Illegal ( link.

Pay Transparency

Zscaler complies with all applicable federal, state, and local pay transparency rules.

Zscaler is committed to providing reasonable support (called accommodations or adjustments) in our recruiting processes for candidates who are differently abled, have long term conditions, mental health conditions or sincerely held religious beliefs, or who are neurodivergent or require pregnancy-related support.