Senior Software Security Engineer (PHP)

Senior Software Security Engineer (PHP)


The Wikimedia Foundation is looking for a Senior Software Security Engineer to join the Product Security team to build new security technologies to protect Wikipedia and our other projects. This is a very hands-on engineering role working alongside our other security team members to design and code new features to protect and reassure our users and to ensure the platform remains resilient against attacks.

YOU ARE …a smart developer with experience building security features in large-scale systems. You understand the importance of testing and documentation, and common pitfalls in developing secure web applications. You must have a passion for the WMF mission. We do (almost) everything publicly and the work we do touches thousands of editors every day.

You will be working primarily on our MediaWiki platform which powers Wikipedia. As a top 10 website, we must meet stringent performance standards while addressing new security challenges such as supporting modern authentication technologies, detecting and preventing platform abuse from bots, and planning and rolling out improvements to our security architecture by defending against emerging security threats.

You are responsible for:

  • Help design and build MediaWiki security capabilities
  • Review and deploy security features developed by the Foundation and community members
  • Work with other development teams to ensure that they make safe architectural and implementation choices
  • Perform security maintenance and address technical debt in security-critical components
  • Provide support for application security incidents and operations

Skills and Experience:

  • Strong software engineering experience with a focus on security
  • Ability to work effectively in a modern, object-oriented PHP code-base
  • Experience developing client-side JavaScript
  • Experience in developing secure software or security-related product features
  • A strong interest in working with a talented security team and learning more specialist security skills such as exploiting and mitigating application-level vulnerabilities
  • Patience in explaining security issues and their implications on privacy and risk to non-technical audiences
  • Sensitivity to the security challenges faced by participants in a large, international project
  • Experience using Linux at the command line for tasks related to web application development and deployment
  • Ability to maintain focus when working remotely

Additionally, we’d love it if you have:

  • Experience working on anti-abuse mechanisms such as CAPTCHA and bot detection
  • Previous experience building security countermeasures against attacks on technologies at the web, backend and database level
  • Experience finding and fixing security bugs and reviewing code for security gaps
  • A working knowledge of threat modeling and secure design patterns

About the Wikimedia Foundation

The Wikimedia Foundation is the nonprofit organization that operates Wikipedia and the other Wikimedia free knowledge projects. Our vision is a world in which every single human can freely share in the sum of all knowledge. We believe that everyone has the potential to contribute something to our shared knowledge, and that everyone should be able to access that knowledge freely. We host Wikipedia and the Wikimedia projects, build software experiences for reading, contributing, and sharing Wikimedia content, support the volunteer communities and partners who make Wikimedia possible, and advocate for policies that enable Wikimedia and free knowledge to thrive. 

The Wikimedia Foundation is a charitable, not-for-profit organization that relies on donations. We receive donations from millions of individuals around the world, with an average donation of about $15. We also receive donations through institutional grants and gifts. The Wikimedia Foundation is a United States 501(c)(3) tax-exempt organization with offices in San Francisco, California, USA.

As an equal opportunity employer, the Wikimedia Foundation values having a diverse workforce and continuously strives to maintain an inclusive and equitable workplace. We encourage people with a diverse range of backgrounds to apply. We do not discriminate against any person based upon their race, traits historically associated with race, religion, color, national origin, sex, pregnancy or related medical conditions, parental status, sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, or any other legally protected characteristics.

The Wikimedia Foundation is a remote-first organization with staff members including contractors based 40+ countries*. Salaries at the Wikimedia Foundation are set in a way that is competitive, equitable, and consistent with our values and culture. The anticipated annual pay range of this position for applicants based within the United States is US$ 105,309   to US$ 163,646   with multiple individualized factors, including cost of living in the location, being the determinants of the offered pay. For applicants located outside of the US, the pay range will be adjusted to the country of hire. We neither ask for nor take into consideration the salary history of applicants. The compensation for a successful applicant will be based on their skills, experience and location. 

*Please note that we are currently able to hire in the following countries: Australia, Austria, Bangladesh, Belgium, Brazil, Canada, Colombia, Costa Rica, Croatia, Czech Republic, Denmark, Egypt, Estonia, Finland, France, Germany, Ghana, Greece, India, Indonesia, Ireland, Israel, Italy, Kenya, Mexico, Netherlands, Nigeria, Peru, Poland, Singapore, South Africa, Spain, Sweden, Switzerland, Uganda, United Arab Emirates, United Kingdom, United States of America and Uruguay.  Our non-US employees are hired through a local third party Employer of Record (EOR). 

We periodically review this list to streamline to ensure alignment with our hiring requirements. 

All applicants can reach out to their recruiter to understand more about the specific pay range for their location during the interview process.

If you are a qualified applicant requiring assistance or an accommodation to complete any step of the application process due to a disability, you may contact us at or +1 (415) 839-6885.

More information

U.S. Benefits & Perks
Wikimedia Foundation
Applicant Privacy Policy
News from across the Wikimedia movement
Wikimedia 2030
Our Commitment to Equity
This is Wikimedia Foundation 
Facts Matter
Our Projects
Our Tech Stack