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Senior Performance Engineer - QA in Valencia


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Job Description

We are looking for people who are sharp, creative and hardworking, with an unwavering desire to be the best.

Traditional security companies are becoming less relevant as cloud adoption and digital transformation become the norm in every market industry and every market segmentation. Zscaler has been a leader in Gartner’s MQ for 9 consecutive years and has helped shape the emerging SASE category (a true category creator). We are well-positioned to dominate this massively growing cloud security market.

The Zscaler Culture

Winning Technology and Products -We offer the best technology and products for the Cloud First world. We pioneered cloud security and continue to grow our 20B + TAM by releasing new products every year.
Supportive Leadership – An industry-leading leadership team with strong values, off the chart business acumen that will help you succeed quickly while providing mentorship and career growth.
Competitive; We Play to Win – We are playing in a Rapidly growing TAM and huge market mega-shifts that leads directly to Zscaler; tracking a growth path similar to Salesforce, Workday, & ServiceNow

We have a terrific opportunity in our  Zscaler Remote Browser Isolation team for a Sr. Infrastructure Engineer. 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.

Zscaler is looking for an agile and hands-on performance engineer that has a unique combination of skills and wants to develop professionally inside a world-class engineering team. The ideal candidate will play an important role in all phases of the performance engineering journey of our product from test cases design, to running and collecting results through implementation of test strategies and analysis of the performance metrics for our Browser Isolation technology.

About the Team

The Browser Isolation Platform is a small distributed team that works fast and lives on the cutting edge of software engineering in backend, frontend and infrastructure. We like open-source but we are not afraid of building stuff ourselves where it makes sense and we can optimize something. Our

philosophy is: done is better than perfect and we strive to work iteratively and optimize our processes along the way so that we can achieve reliable and fast product deliverables that delight our customers. The environment is fast-paced and requires the ability to take initiative and manage ambiguity to drive effective results. This role may interface with customers, subject matter experts, technical experts, developers and other QA engineers located globally and in different time zones. 


  • Design, perform load, stress and scalability tests to validate system performance and stability.
  • Analyze tests results and work with Developers and Engineers to perform bug fixes.
  • Provide technical assistance to improve system performance, capacity, reliability and scalability.
  • Identifying areas/components that are critical to system performance, performance KPIs and capture non functional requirements
  • Analyze performance results to identify system inefficiencies and suggest optimizations to address the same.
  • Plan performance tests both in QA and pre-prod (sometimes production).
  • Develop, document, and maintain the test strategy and test scenarios
  • Assist in the design, development and support of software needed to execute performance tests
  • Generate periodic performance reports for stakeholders to review


  • Demonstrable experience in QA and performance testing
  • Good coding skills in one or more of the following languages: Python, Go, Java or JavaScript
  • Ability to convert customer issues to automated performance tests.
  • Experience in testing the performance of REST APIs and microservice architecture.
  • Experience using diagnostic tools like HTTP Watch, Fiddler IE and Chrome Developer Tools.
  • Experience with running large scale performance tests in a distributed architecture/environment
  • Solid communication skills: demonstrated ability to explain complex technical issues to both technical and non-technical audiences.
  • Self-directed and self-motivated individual who takes complete ownership of the product and its outcome.
  • Experience in root cause analysis to identify bottlenecks in performance tests
  • Experience in profiling, and tracing represents a plus
  • Exceptional English communication skills, both written and verbal. This includes listening skills and an open attitude toward constructive feedback.
  • Ability to work both with a global team and individually

Why Zscaler?

People who excel at Zscaler are smart, motivated and share our values. Ask yourself: Do you want to team with the best talent in the industry? Do you want to work on disruptive technology? Do you thrive in a fluid work environment? Do you appreciate a company culture that enables individual and group success and celebrates achievement? If you said yes, we’d love to talk to you about joining our award-winning team.


About Zscaler

  • Cyber Security

  • San Jose, CA, USA

  • 1,000-5,000

  • 2008

We’re on a mission to make the internet your new secure corporate network.

Back in the day when your users were all on the network and your applications resided in your physical data center, it made sense to establish a secure perimeter around your network. But those days are over, the perimeter is gone, and network security is all but irrelevant.

Instead, you need to put your defenses 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 reside.

By moving applications and infrastructure to the cloud and untethering employees from their desks, you can realize tremendous advantages in productivity, agility, and cost containment. With our 100% cloud built secure platform, Zscaler can help you make the move to the cloud, securely.

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