Principal Software Development Engineer

Role

We are looking for a Principal Software Development Engineer to join our team. This is a hybrid role based in San Jose, CA, reporting to the Director, Software Engineering in the Engineering department. You will join the team that built the world’s largest cloud security platform from the ground up, enabling organizations worldwide to harness speed and agility with a cloud-first strategy. With more than 100 patents and 15 million users across 185 countries, you will bring your vision to a team of experts dedicated to enhancing our multitenant architecture and global footprint.

What you’ll do (Role Expectations)

• Designing, developing, and optimizing the system, including networking and security features, to support high-performance applications. Creating design and functional specification documents while performing unit testing and automation to ensure quality
• Applying strong software design principles and deep troubleshooting expertise to deliver scalable, resilient, and impactful improvements to Zscaler’s Zero Trust Security Services
• Work directly with Engineering Architects, Product Managers, Customers, Solution Architects to understand customer use cases. Review PRDs. Collaborating with cross-functional teams to identify and resolve system-related issues, optimize system performance, and innovate features
• Coach and mentor junior team members and ensure highest level of quality deliverables
• Ensuring federal certifications such as FIPS, FedRAMP, Common Criteria, and SOC2 compliance

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)

• Bachelor's or Master's (preferred) degree in Computer Science or a related field with 10+ years of experience in system engineering for high-performance networking
• Expertise in Linux kernel-based networking (L2/L3), stateful firewalls, NAT, network drivers, Routing protocols(BGP, OSPF, PIM), and protocols like VLANs, DHCP, DNS, SSL, DTLS, QUIC, IPsec, GRE and Wireguard
• Proficiency in Go and Python programming languages with excellent problem-solving skills for debugging complex data path issues
• Foundational understanding of AI/ML technologies and experience leveraging, securing, or positioning AI-driven solutions to optimize outcomes within your functional domain
• Strong communication and collaboration skills to work effectively with cross-functional teams in a high-accountability environment while designing scalable systems

What Will Make You Stand Out (Preferred Qualifications)

• Experience integrating AI/ML frameworks or intelligent data path analysis models to optimize kernel-level networking performance and automate predictive threat detection
• Experience in technologies such as wireguard, various tunneling protocols such as GRE, L2VPN, HA protocols such as VRRP alongside certifications like FIPS or FedRAMP and prior experience with TLS, DTLS, QUIC
• Familiarity with cloud computing platforms like AWS or Azure, containerization technologies such as Docker and Kubernetes, and advanced virtualization or security solutions