About Zscaler

Serving thousands of enterprise customers around the world including 40% of Fortune 500 companies, Zscaler (NASDAQ: ZS) was founded in 2007 with a mission to make the cloud a safe place to do business and a more enjoyable experience for enterprise users. As the operator of the world’s largest security cloud, Zscaler accelerates digital transformation so enterprises can be more agile, efficient, resilient, and secure. The pioneering, AI-powered Zscaler Zero Trust Exchange™ platform protects thousands of enterprise customers from cyberattacks and data loss by securely connecting users, devices, and applications in any location. 

Named a Best Workplace in Technology by Fortune and others, Zscaler fosters an inclusive and supportive culture that is home to some of the brightest minds in the industry. If you thrive in an environment that is fast-paced and collaborative, and you are passionate about building and innovating for the greater good, come make your next move with Zscaler. 

Job Title: Principal Software Engineer ~ Core Team

Locations:  Europe (preferably Spain, Remote is an option), India

Zscaler (NASDAQ: ZS) accelerates digital transformation so that customers can be more agile, efficient, resilient, and secure. The Zscaler Zero Trust Exchange is the company’s cloud-native platform that protects thousands of customers from cyberattacks and data loss by securely connecting users, devices, and applications in any location. 

With more than 10 years of experience developing, operating, and scaling the cloud, Zscaler serves thousands of enterprise customers around the world, including 450 of the Forbes Global 2000 organisations. In addition to protecting customers from damaging threats, such as ransomware and data exfiltration, it helps them slash costs, reduce complexity, and improve the user experience by eliminating stacks of latency-creating gateway appliances. 

Zscaler was founded in 2007 with a mission to make the cloud a safe place to do business and a more enjoyable experience for enterprise users. Zscaler’s purpose-built security platform puts a company’s defences and controls where the connections occur—the internet—so that every connection is fast and secure, no matter how or where users connect or where their applications and workloads reside.

Job Description

We want you to be our colleague in the Core Team, part of the Cloud Browser Isolation product. Our purpose is to explore new ways of making browser isolation user experience one of the best in the market and, why not, the best.


We are a distributed team that works fast and lives on the cutting edge of backend, frontend and infrastructure software engineering. 


We favour open-source reuse but we are not afraid of building stuff ourselves where it makes sense.. 

This role may interface with customers, subject matter experts, technical experts, developers and QA engineers located globally and in different time zones.


The Staff Software Engineer will report to the Senior Engineering Manager.


Zscaler is looking for a seasoned and agile software engineer that has a unique combination of skills. The ideal candidate will play a key role in all phases of the product development cycle, from definition, design, through implementation, test, release and monitor of components of  Browser Isolation Platform, Core team.  


This is an excellent opportunity to join a small, dynamic team that is working on cutting edge Browser Isolation technology to evolve our current cloud security flagship products: ZIA and ZPA.



  • Complete ownership of multiple components definition, design, implementation, testing, delivery and monitor, according to the team's area of responsibility.
  • Analyse product requirements and translating into a feasible technical solution.
  • Design highly available and scalable solutions with security in mind for public cloud applications.
  • Write correct, maintainable, portable, testable, secure, performant and reliable code of our current components and future components.
  • Write unit / integration / e2e / performance / resilience tests where it makes sense and integrate them in our CI/CD flow.
  • Build quick MVPs / POCs to validate technical solutions.
  • Act as a mentor and a leader to all (especially junior) team members.


  • Great communication and interpersonal skills
  • 10+ years of experience in software engineering 
  • 4+ years of modern C++ (C++ 11 or later)
  • 3+ years of Chromium or WebKit development experience
  • 3+ years of Linux experience
  • Knowledge of one or more of the following programming languages:
    • JavaScript
    • Python
    • Golang
    • Rust
  • Exposure to Docker and Kubernetes in a production environment
  • Ability to troubleshoot complex systems
  • Build systems, Continuous Integration (Jenkins or similar) 
  • Solid understanding of data structures, algorithms, systems design and programming principles
  • A keen interest in security and performance 
  • Comfortable with scoping effort and estimating development tasks
  • Be willing to learn new technologies


Nice to have:

  • Experience in dealing with low latency networking
  • Experience in working with low level networking protocols (TCP, UDP or custom protocols) is a plus or known or custom protocols
  • Experience with cloud deployments (AWS, GCP or Azure) 
  • Web technologies such as WebAudio, WebGL, WebAssembly




By applying for this role, you adhere to applicable laws, regulations, and Zscaler policies, including those related to security and privacy standards and guidelines.

Zscaler is proud to be an equal opportunity and affirmative action employer. We celebrate diversity and are committed to creating an inclusive environment for all of our employees. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy or related medical conditions), age, national origin, sexual orientation, gender identity or expression, genetic information, disability status, protected veteran status or any other characteristics protected by federal, state, or local laws.

See more information by clicking on the Know Your Rights: Workplace Discrimination is Illegal link.

Pay Transparency

Zscaler complies with all applicable federal, state, and local pay transparency rules. For additional information about the federal requirements, click here.

Zscaler is committed to providing reasonable support (called accommodations or adjustments) in our recruiting processes for candidates who are differently abled, have long term conditions, mental health conditions or sincerely held religious beliefs, or who are neurodivergent or require pregnancy-related support.

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