# Principal Security Engineer

**Company:** [Square](https://hotfix.jobs/companies/square)
**Location:** California
**Role:** Security Engineering
**Salary:** $319k – $479k/yr
**Experience:** 10+ years
**Skills:** Security Architecture, Threat Modeling, Secure Sdlc, Security Automation, System Design, Tokenization, Mobile Security, Secreleng
**Posted:** 2026-06-30

> Principal Security Engineer responsible for setting the bar for software security excellence at Block. Defines multi-year technical strategy, leads development of high-leverage security solutions and infrastructure across business units, drives Secure by Design culture, and mentors InfoSec teams. Requires 10+ years shipping production software with 5+ years scaling security practices.

## Job Description

## 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).

## Similar roles

- [Principal Infrastructure Security Engineer](https://hotfix.jobs/jobs/fdaecf48-c221-4556-b4cf-722bfc4d05ed) - Crusoe - San Francisco, CA - $280k – $330k/yr
- [Principal Software Engineer II - Product Security](https://hotfix.jobs/jobs/09bd6c52-42a3-4c57-82dd-dcb03292fb85) - Snowflake - Menlo Park, CA - $280k – $403k/yr
- [Principal Engineer, Authentication](https://hotfix.jobs/jobs/6951d447-8a37-4257-b626-ee033a79d9b8) - Databricks - Remote - $280k – $385k/yr
- [Principal Engineer - Privacy](https://hotfix.jobs/jobs/7832d3b3-421d-475e-acde-1b8d426b086f) - Databricks - Mountain View, CA - $278k – $339k/yr
- [Principal Security Engineer, Infrastructure Security](https://hotfix.jobs/jobs/d8d28d9c-8c13-486a-803c-cf5582aafe17) - OpenAI - Remote - $278k – $490k/yr

**Apply:** https://hotfix.jobs/jobs/40a2458a-4a6c-488f-9347-eec2d58c26c2
**Canonical:** https://hotfix.jobs/jobs/40a2458a-4a6c-488f-9347-eec2d58c26c2