Senior Software Engineer, Mobile Security

  • New York, NY
  • Full-time

Company Description

When we launched the little white reader, we invented mobile, ubiquitous payments and enabled anyone to start, run, and grow a business. Ten years and billions of transactions later we’re reimagining commerce for businesses of all types and sizes—we’re enabling the independent electrician to send invoices, helping the beauty salon pay its employees, and giving the burgeoning coffee chain capital for a second, third, and fourth location. We’re working to find new and better ways to help businesses succeed on their own terms—and we’re looking for people like you to help shape tomorrow at Square.

Job Description

We work to guarantee the security of every transaction from dip and tap to receipt. In the Mobile Security group, we work to collect, interpret, and react to signals which identify security risks to our mobile apps and the APIs they depend on. We build workflows, both human and machine, to make real-time and asynchronous decisions about the risks associated with these devices. We make attacking Square difficult, so that our sellers and buyers stay safe.

We seek high-scale software service engineers, who can deal with the complexity of security in a high QPS environment. We need people who recognize that a false positive is a frustrated customer, a false negative a possible security risk, and an engineer’s oversight a precious and limited commodity. We cannot succeed without elegant tooling, automated security decisions, and well-defined processes to help leverage ourselves.

You will: 

  • Lead and contribute to software engineering projects. Prior projects have involved:
    • Java development in a scaled environment
    • High-traffic data processing and rules-based analysis
    • Information flow modeling
    • Applied machine learning for predictive analysis
    • Work in the San Francisco, New York or Seattle office. Remote work in the USA or Canada is a possibility depending on experience. Occasional travel may be required.


You have:

  • Strong examples of secure and elegant software development on production systems
  • Skill in Java service development
  • A curiosity about applied information security

Additional Information

At Square, our purpose is to empower – within and outside of our walls. In order to build the best tools for the businesses and customers we support all over the world, we have to start at home with a workforce as diverse and empowered as our sellers. To this end, we take great care to evaluate all employees and job applicants equally, based on merit, competence, and qualifications. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status, or any other characteristic protected by law. We encourage candidates from all backgrounds to apply and always consider qualified applicants with arrest and conviction records, in accordance with the San Francisco Fair Chance Ordinance. Applicants in need of special assistance or accommodation during the interview process or in accessing our website may contact us by sending an email to assistance(at) We will treat your request as confidentially as possible. In your email, please include your name and preferred method of contact, and we will respond as soon as possible. Perks At Square, we want you to be well and thrive. Our global benefits package includes: Healthcare coverage, Retirement Plans, Employee Stock Purchase Program, Meal reimbursements, Wellness perks, Paid parental leave, Flexible time off, Learning and Development resources