Senior Software Engineer; C ​/Networking​/Dataplane

Senior Staff Software Engineer (C / Networking / Dataplane)

San Jose, California, USA

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.

We are looking for a Senior Staff Software Engineer (C / Networking / Dataplane) to join our Engineering Team. This is a Hybrid (San Jose, CA 3 days a week in office) role, reporting to the Senior Director, Software Development Engineering. The Senior Staff Software Engineer will design and implement high‑performance datapath features for load balancing and L7 protocols, directly enhancing the scalability and security of global networking infrastructure.

Leveraging deep C programming expertise and autonomous ownership, you will drive complex architectural projects from initial concept to large‑scale deployment.

• Design and implement datapath features related to Load Balancer, Firewall rules and L7 Protocol implementations
• Apply deep knowledge of C programming, data structures, and algorithms to build high‑performance systems
• Independently drive moderately complex projects from conception to deployment with full ownership
• Utilize expert knowledge of networking protocols and services including DNS, HTTP, TCP/IP, and SSL/TLS
• Leverage Unix or Linux operating systems knowledge to optimize networking and security applications

• Act as an owner; passion for the mission fuels bias for action. Operate with integrity and navigate seamlessly between high‑level strategy and hands‑on execution.
• A high‑trust collaborator; ambitious for the team and embrace challenge culture by giving and receiving ongoing feedback with candor, clarity, and respect.
• Customer‑obsessed; build deep empathy for internal and external customers, anchoring decisions in solving real‑world problems and championing their needs from start to finish.
• Operate with urgency, delivering high‑impact results quickly in a high‑growth environment.
• Think at scale; connect day‑to‑day work to the larger company mission and build solutions, processes, and teams that last and support a global organization.

• Demonstrated curiosity and active exploration of AI tools, with a proven history of integrating new technologies to enhance daily workflows and augment problem‑solving.
• 8+ years of experience building large‑scale commercial networking and security applications with proficiency in C or C++.
• Strong foundational knowledge in data structures and algorithms.
• Working experience in Linux, Unix, or similar operating systems.
• BS or MS degree in CS/CE or equivalent experience.

• Exposure to AI‑assisted software development tools and workflows, with the ability to apply them to improve engineering productivity and delivery quality.
• Advanced knowledge of networking protocols and services, specifically DNS, HTTP,…