Principal Software Development Engineer

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 looking for a Principal Software Engineer to join our team. This is a hybrid role based in Bangalore, reporting to the Sr. Director of Software Engineering within the Platform Convergence department. You will design and build a low-latency, high-throughput data forwarding plane using Rust, leveraging its async/await model for efficient I/O and service-oriented infrastructure. You will develop distributed, scalable systems with a focus on concurrency and fault tolerance to bridge the gap between control and orchestration layers. What you’ll do (Role Expectations) - Design and build a low-latency, high-throughput data forwarding plane using Rust and async/await models for efficient service-oriented infrastructure - Develop distributed, scalable systems with a heavy focus on concurrency, fault tolerance, and messaging - Implement and maintain gRPC-based APIs and services to integrate forwarding plane capabilities with control and orchestration layers - Optimize system performance through deep profiling across kernel-space and user-space - Drive technical excellence through code reviews, architectural discussions, documentation, and mentoring junior engineers 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) - 10+ years of software development experience with specific expertise in systems programming and Rust - Extensive experience with async frameworks such as Tokio or async-std - Proven track record of building resilient, observable, and horizontally scalable distributed systems - Deep understanding of Linux fundamentals, including networking, namespaces, sockets, and kernel-user space interaction - Proficiency in container-based environments, Git, CI/CD workflows, and performance instrumentation What Will Make You Stand Out (Preferred Qualifications) - Professional experience with systems languages like C/C++ or Go in performance-critical environments - Familiarity with Linux networking stacks and kernel-space technologies like eBPF, XDP, or DPDK - Hands-on experience with gRPC, Protobufs, and L2–L4 networking protocols including TCP/IP, UDP, and QUIC #LI-Hybrid #LI-SU1 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 perspec