Senior Software Engineer (C, Networking)

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.

Role

We are looking for a seasoned Senior Software Development Engineer to join our team. This is a hybrid role based in San Jose, CA (3 days a week), reporting to the Director, Software Engineering within the Digital Experience department. Our Engineering team built the world’s largest cloud security platform from the ground up, and we keep building. You will bring your vision and passion to our team as you design and code components of a large-scale distributed system, enabling organizations worldwide to harness speed and agility with a cloud-first strategy.

What you’ll do (Role Expectations)

• Participating in all phases of the product development cycle, from definition and design to implementation and testing

• Developing functional specifications, assessing task requirements and schedules, and contributing to development, debugging, and support

• Designing and coding components of a large-scale distributed system with a focus on high performance and scalability, and troubleshooting issues efficiently

• Collaborating with feature teams, Operations, and Support to maintain a healthy cloud environment and ensure customer satisfaction

• Demonstrating accountability and ownership for areas assigned to you

Who You Are (Success Profile)

• 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.

What We’re Looking for (Minimum Qualifications)

• 3+ years of software development experience in programming with C, Python, or high-level languages

• Experience in software development on Unix/Linux systems

• Experience working with REST APIs and API gateways

• Knowledge of L4 to L7 network topologies and TCP/IP networking stacks

• Familiarity with observability and monitoring products

What Will Make You Stand Out (Preferred Qualifications)

• Strong fundamentals in operating system concepts, event-based programming, multi-threading, memory optimization, and fault tolerance

• Familiarity with endpoint security and firewalls

• Experience developi