Sr. Software Development Engineer

About the role

Zscaler is looking for a senior developer to join the ThreatLabz department. You will design and maintain web applications while taking ownership of end-to-end feature modules within our security research infrastructure. In this capacity, you will drive the full lifecycle of critical security features from initial concept through production deployment and ongoing maintenance. You will act as a technical owner for complex components, ensuring that high-quality, scalable solutions are delivered on schedule. The role requires deep collaboration with security researchers to translate threat intelligence and investigative needs into robust software capabilities. You will be responsible for ensuring that the applications you build are not only functional but also secure, performant, and resilient under demanding conditions. This position offers the opportunity to work on the foundational tools that power one of the largest cloud security platforms in the industry.

Key facts

What you'll do

• Develop and scale server-side applications, microservices, and secure RESTful APIs using Python, Node.js, Django, or Flask to handle high-volume security data.
• Configure application security, including authentication, authorization protocols, and data protection mechanisms to meet enterprise standards.
• Architect and refine database schemas for PostgreSQL, MySQL, and MongoDB, optimizing for both performance and data integrity.
• Build responsive frontend interfaces using HTML5, CSS3, JavaScript, TypeScript, and modern frameworks to deliver clear and actionable security insights.
• Partner with the Cyber Threat Research organization on code reviews, unit testing, and software maintenance to ensure best practices are followed.
• Design and implement integrations with external data sources and internal platforms, ensuring seamless data flow and consistency.
• Troubleshoot complex production issues, analyzing logs and system metrics to identify root causes and implement effective fixes.
• Collaborate with cross-functional teams to define, refine, and prioritize technical requirements and deliverables.
• Mentor junior developers by providing guidance on architecture, coding standards, and debugging techniques.
• Stay current with emerging security trends and technologies to proactively suggest improvements to the development roadmap.
• Translate ambiguous requirements into concrete technical specifications and implementation plans.
• Own the deployment pipeline, ensuring that releases are reliable, traceable, and minimally disruptive to operations.
• Write comprehensive documentation for both technical and non-technical stakeholders to support maintainability and knowledge transfer.
• Contribute to the open source security community where applicable, sharing insights and solutions that benefit the broader ecosystem.

Requirements

• Minimum of 2-3 years of professional application development experience in a relevant field.
• Proficiency in Python and backend frameworks like Django and Flask for building scalable and maintainable services.
• Experience with database systems including PostgreSQL, MySQL, and MongoDB, along with ORM libraries for efficient data access.
• Expertise in frontend development using HTML5, CSS3, JavaScript, jQuery, and AngularJS to create intuitive user experiences.
• In-depth knowledge of the ELK Stack, covering cluster setup, Logstash, Kibana, Elastic beats, and Elasticsearch for monitoring and analysis.
• Demonstrated experience integrating AI tools and LLMs into development workflows to enhance productivity and capabilities.
• Strong understanding of software development principles such as version control, continuous integration, and testing methodologies.
• Ability to work effectively in a hybrid environment, balancing independent work with collaborative team efforts.

Nice to have

• Skill in Python-based data science libraries like pandas and NumPy for advanced data manipulation and analysis.
• Experience implementing machine learning algorithms for security optimization and threat detection enhancements.
• Familiarity with Agile development practices and ceremonies to ensure iterative and incremental delivery.
• Knowledge of cloud services on AWS, Azure, or GCP for deploying and managing scalable infrastructure.
• Previous experience contributing to security-focused projects or tools that protect users at scale.
• Exposure to threat hunting methodologies and the ability to translate findings into actionable defensive measures.
• Understanding of compliance and regulatory requirements relevant to security and data protection.

Practical notes

• This role is hybrid.
• Benefits include health plans, vacation and sick time, parental leave, retirement options, and education reimbursement.
• Zscaler provides reasonable accommodations for candidates with disabilities, long-term conditions, or other specific needs during the recruiting process.