Senior Product Security Engineer, eCommerce

  • Full-time

Company Description

Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams — People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more — provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.

Job Description

As a Sr. Security Engineer on the Embedded Product Security Engineering team, you will design and build services to address the unique security challenges specific to our ecosystem of startups. In this role, you will integrate with our eCommerce product engineering teams to design and build security solutions to protect the millions of Square sellers online. 

Our Embedded Security Engineering team members embed into high leverage product engineering teams within specific business units to tackle their unique security challenges. We believe in evangelizing security best practices with the teams we embed into and work collaboratively to develop scalable security solutions.

You will:

  • Design, develop, and drive implementation of malicious content and code protections for millions of sellers hosting online stores and sites with Square Online. 

  • Automate detection of and response to malicious usage of Square Online sites (e.g., phishing).

  • Continually improve the security controls applied to our eCommerce checkout platform.

  • Define selection criteria, select, and implement third party security tools and services.

  • Lead integration, adoption, and continuous improvement of developed security solutions. 

  • Work in any Square office location, or work remotely in the USA or Canada


You have:

  • Demonstrated success architecting and building secure systems with broad company impact.

  • Demonstrated technical initiative and leadership.

  • A high bar for writing scalable, robust, and testable code.

  • A strong desire to perform and grow as a security engineer and educate other engineers.

Even better:

  • Familiarity with solutions for addressing web security and malicious content concerns.

  • Experience with HTTP security headers, such as Content-Security-Policy.

  • Experience with automating operations using threat intelligence, such as VirusTotal.

Technologies we use and teach:

  • PHP and Laravel

  • MySQL, Postgres and Cassandra

  • JavaScript and React

Additional Information

We’re working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is a proud equal opportunity employer. We work hard to evaluate all employees and job applicants consistently, without regard to race, color, religion, gender, national origin, age, disability, veteran status, pregnancy, gender expression or identity, sexual orientation, citizenship, or any other legally protected class. 

We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we’re doing to build a workplace that is fair and square? Check out our I+D page

Additionally, we consider qualified applicants with criminal histories for employment on our team, assessing candidates in a manner consistent with the requirements of the San Francisco Fair Chance Ordinance.


We want you to be well and thrive. Our global benefits package includes:

  • Healthcare coverage
  • Retirement Plans
  • Employee Stock Purchase Program
  • Wellness perks
  • Paid parental leave
  • Paid time off
  • Learning and Development resources

Block, Inc. (NYSE: SQ) is a global technology company with a focus on financial services. Made up of Square, Cash App, Spiral, TIDAL, and TBD, we build tools to help more people access the economy. Square helps sellers run and grow their businesses with its integrated ecosystem of commerce solutions, business software, and banking services. With Cash App, anyone can easily send, spend, or invest their money in stocks or Bitcoin. Spiral (formerly Square Crypto) builds and funds free, open-source Bitcoin projects. Artists use TIDAL to help them succeed as entrepreneurs and connect more deeply with fans. TBD is building an open developer platform to make it easier to access Bitcoin and other blockchain technologies without having to go through an institution.

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