Principal Security Engineer

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.
The Role
As a Principal Security Engineer focused on Software Security Engineering at Block, you will be a technical leader reporting to the CISO responsible for setting the bar for security excellence and driving the creation of innovative, world-class software solutions to complex security problems. You will work across Engineering and Information Security (InfoSec) to champion a "Secure by Design" culture, directly influencing the architecture of Block's core products and infrastructure. Your mandate is to provide deep technical expertise and strategic direction to ensure that security is enabling fast, secure innovation across the business.
You Will

• Software Security Innovation: Deliver world-class and innovative software solutions to security problems, tackling Block's top risks such as technology fragmentation and security after-the-fact.
• Technical Strategy & Architecture: Define the multi-year technical strategy for software security at Block, guiding architectural decisions and ensuring alignment with engineering best practices.
• Cross-Cutting Solution Leadership: Identify and lead the development and implementation of common, high-leverage security solutions and infrastructure across Block's business units (Square, Cash App, TBD, etc.) to combat data sprawl and overpermissioning.
• Drive engineering excellence, specifically around security, for critical systems like tokenization platforms, ensuring integrity, performance, and scalability.
• Spearhead the security strategy and engineering excellence for mobile software and platforms across Block's product ecosystem.
• Champion security reliability engineering (SecRelEng) practices to improve the overall resilience and availability of security services and infrastructure.
• Execution Excellence: Lead technical planning and implementation for high-priority security initiatives, acting as a technical decision maker/tie-breaker and upholding high technical standards.
• Consultation & Guidance: Partner with engineering leaders to integrate security practices early into the development lifecycle (Secure SDLC) and provide security architecture review and threat modeling for critical systems.
• Mentorship & Enablement: Foster technical excellence within InfoSec and mentor engineers on technical execution, system design, and technology choices, driving knowledge sharing and documentation.

You Have

• Track record of exemplary technical leadership and decision-making at a Principal or equivalent level (L8+ technical capabilities preferred).
• 10+ years of experience developing and shipping production software and critical services, with a minimum of 5 years focused on establishing and scaling security practices in a large, modern technology environment.
• Mastery of system design and architecture, with demonstrable experience solving ambiguous, domain-heavy problems by structuring the approach, clarifying scope, and driving clarity among stakeholders.
• Deep technical understanding of security vulnerabilities, risks, countermeasures, and compensating controls, particularly in high-volume, real-time transaction processing environments.
• Exceptional collaboration and communication skills, with proven ability to influence executive leadership and direct engineering teams in prioritizing security roadmap items to balance security and business risks.
• Demonstrable ability to write production-quality code/script for security automation and tooling.

Preferred:

• Experience leading and driving significant technical initiatives across multiple team, organizational and product boundaries.
• Experience in the financial technology, payments, or cryptocurrency/bitcoin domain, reflecting Block's unique security characteristics.
• Experience improving engineering standards and practices for security, and building systems to achieve sub-linear growth of security resources relative to the business (Design for Leverage, Not Coverage).

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 an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances.
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 .
While there is no specific deadline to apply for this role, U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted.
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.
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.
Zone A:
$319,000 - $478,600 USD
Zone B:
$319,000 - $478,600 USD
Zone C:
$319,000 - $478,600 USD
Zone D:
$319,000 - $478,600 USD
Application Guidelines
Candidates may submit up to 9 active applications within a 60-day period. Reapplications to the same role are accepted 90 days after a previous application has been reviewed.
Use of AI in Our Hiring Process
We may use automated AI tools to evaluate job applications for efficiency and consistency. These tools comply with local regulations, including bias audits, and we handle all personal data in accordance with state and local privacy laws.
Contact us here with hiring practice or data usage questions.
Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block.
Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we're helping build a financial system that is open to everyone.