Principal Security Engineer

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.
• 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.

Technical Strategy & Architecture

• Define the multi-year technical strategy for software security at Block, guiding architectural decisions and ensuring alignment with engineering best practices.
• 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.

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).