Senior Application Security Engineer

  • 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

Protect the Future of Finance
Block's Offensive Security team is on a mission to safeguard the financial systems of tomorrow. We're seeking a seasoned Senior Application Security Engineer to join our elite squad of security engineers. As a key player on our team, you'll be responsible for identifying and crushing security vulnerabilities in our applications, ensuring the integrity of our systems, and protecting the trust of our customers. We don't throw security problems over the wall. We understand the struggle of our engineers and provide contextual guidance for a diverse, complex and cutting edge tech stack that enables the business. We don't work in isolation, engineering and security teams at Block are our partners. We collaborate with our partners at every opportunity we can find and place the needs of our partners at the highest priority. 

Your Mission:

  • Conduct penetration tests, source code reviews, and design reviews to uncover hidden security threats
  • Participate in red and purple team operations, outsmarting attackers and fortifying our defenses
  • Dive deep into our tech stack to develop a mastery of our applications and services
  • Stay one step ahead of threat actors, understanding their tactics and motivations
  • Review and improve the designs of complex systems, ensuring they're secure by design
  • Communicate critical security findings to cross-functional teams, providing contextual remediation steps and guiding resolutions every step of the way
  • Help respond to incidents and reproduce bug bounty reports.


Your Secret Weapons:

  • 5+ years of experience in penetration testing, with a proven track record of being able to write proof-of-concept exploits that demonstrate impact.
  • Exceptional communication, collaboration, and problem-solving skills.
  • Ability to work independently, managing multiple projects with ease and navigating technically complex apps and services. 
  • In-depth knowledge of secure design patterns
  • Bonus points for experience with:
    • AWS Security
    • AI Security
    • Red teaming
    • Kubernetes and Docker security
    • Mobile app security

What You'll Get:

  • The opportunity to make a real impact on the security of our applications and the financial industry as a whole.
  • A collaborative and dynamic work environment with a team of security experts.
  • Freedom to do security research that has the potential to have a deep impact on Block.
  • An environment where conference presentations are highly encouraged.

Additional Information

Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate’s starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.

Zone A: USD $171,800 - USD $257,600
Zone B: USD $163,200 - USD $244,800
Zone C: USD $154,600 - USD $232,000
Zone D: USD $146,000 - USD $219,000

To find a location’s zone designation, please refer to this resource. If a location of interest is not listed, please speak with a recruiter for additional information. 

Full-time employee benefits include the following:

  • Healthcare coverage (Medical, Vision and Dental insurance)
  • Health Savings Account and Flexible Spending Account
  • Retirement Plans including company match 
  • Employee Stock Purchase Program
  • Wellness programs, including access to mental health, 1:1 financial planners, and a monthly wellness allowance 
  • Paid parental and caregiving leave
  • Paid time off (including 12 paid holidays)
  • Paid sick leave (1 hour per 26 hours worked (max 80 hours per calendar year to the extent legally permissible) for non-exempt employees and covered by our Flexible Time Off policy for exempt employees) 
  • Learning and Development resources
  • Paid Life insurance, AD&D, and disability benefits 

These benefits are further detailed in Block's policies. This role is also eligible to participate in Block's equity plan subject to the terms of the applicable plans and policies, and may be eligible for a sign-on bonus. Sales roles may be eligible to participate in a commission plan subject to the terms of the applicable plans and policies. Pay and benefits are subject to change at any time, consistent with the terms of any applicable compensation or benefit plans.

US and Canada EEOC Statement

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, 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, and always assess candidates on an individualized basis.


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.

While there is no specific deadline to apply for this role, on average, U.S. open roles are posted for 70 days before being filled by a successful candidate.

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