Sr. 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 Sr. Software Developer to join our team. This is a Hybrid role, reporting to the Leader in the Tools & Technology Team in the ThreatLabz department. The Sr. Software Developer will be primarily responsible for designing, building, and maintaining client-side and server-side web applications, taking ownership of end-to-end feature modules and ensuring seamless communication between user-facing interfaces and backend infrastructure. Working within ThreatLabz, the world-class security research arm of Zscaler, this role contributes directly to hunting new threats and protecting millions of global users. What you’ll do (Role Expectations) Build and scale server-side web applications, secure RESTful APIs, and microservices using Node.js, Python, Django, or Flask Manage core application security settings, user authentication, authorization protocols, and data protection measures Map and optimize database schemas using relational systems like PostgreSQL or MySQL and NoSQL engines like MongoDB Build responsive, high-performance user interfaces and reusable frontend modules utilizing HTML5, CSS3, JavaScript/TypeScript, and modern frameworks Collaborate closely with the ThreatLabz Cyber Threat Research organization to conduct code reviews, perform unit testing, and maintain software applications 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 Lookin…