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 shar...