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

For over 20 years, Smartsheet has empowered teams to manage work seamlessly and scale solutions smarter. Now, in our most ambitious chapter yet, we are uniting human teams with AI agents. By orchestrating the work agents do best, automating manual tasks and uncovering insights at scale, we create the space for people to focus on what truly matters: judgment, creativity, and big thinking. That is magic at work, and it’s what we show up for every day. AI is reshaping what product security can accomplish, both as a target and as a tool. We're looking for a Principal Security Engineer to own the highest-leverage application security work at Smartsheet: leading threat modeling and product security reviews across a modern SaaS platform used by millions of customers, serving as the team's technical authority on AI security risk, and setting the technical standard for application security practice across the engineering organization. This is the most senior individual contributor role on the Application Security team. The expectation is not just depth: it is reach. You will engage product and engineering leadership directly, drive security requirements rather than advisory recommendations, and build team capability over time. If you are a security engineer who thinks upstream, builds threat models that generate concrete test scenarios and can translate technical findings into architecture decisions and business outcomes, this role is built for you. This role reports to the Manager, Application Security and can be based in our Bellevue, WA office or remotely from anywhere in the US where Smartsheet is a registered employer. You Will: Lead Threat Modeling and Product Security Reviews: Own threat modeling and product security review as the team's primary upstream capability: build models from architecture and data-flow artifacts, derive concrete abuse cases and test scenarios, and drive security requirements into designs before they ship. Define and lead the product secu

Principal Security Engineer Location: London (Hybrid) | Practice Area : Technology & Engineering | Type: Permanent Lead advanced security engineering initiatives that safeguard the future of digital finance The Role As a Principal Security Engineer at Capco, you’ll lead the design and implementation of secure systems and processes across cloud and on-premise platforms. You’ll collaborate closely with engineering and client teams to embed security-by-design principles throughout the SDLC, integrate automated security tooling, and ensure resilience against evolving cyber threats. You’ll also use approved AI tools and AI-enabled workflows where appropriate to improve the speed, quality and effectiveness of security engineering, while maintaining human judgement, responsible AI guardrails and appropriate review and escalation. What You’ll Do Design and implement enterprise-wide security controls and frameworks, using approved AI and automation where appropriate to improve security outcomes Embed security controls into CI/CD pipelines (SAST, SCA, DAST, container scanning) and enable secure SDLC practices Collaborate across teams to champion secure development practices and responsible use of AI-enabled security workflows Lead vulnerability assessments, code reviews and security audits across infrastructure and applications, maintaining appropriate human review, audit trails and escalation pathways Develop and evolve security standards, engineering patterns and data protection strategies What We’re Looking For Strong hands-on experience with Palo Alto, Microsoft or similar security ecosystems Deep understanding of cloud security for AWS, Azure or GCP platforms Proven expertise in secure coding, endpoint protection, SIEM and IAM Familiarity with frameworks and standards such as ISO 27001, NIST and OWASP, alongside an understanding of responsible AI, security guardrails and human-in-the-loop controls Proficiency in Python, Bash, PowerShell or Go for security automation

About the Team Security is at the foundation of OpenAI’s mission to ensure that artificial general intelligence benefits all of humanity. The Security team protects OpenAI’s technology, people, and products. We are technical in what we build but are operational in how we do our work, and are committed to supporting all products and research at OpenAI. Our Security team tenets include: prioritizing for impact, enabling researchers, preparing for future transformative technologies, and engaging a robust security culture. About the Role OpenAI is seeking a Principal Security Engineer to join our Infrastructure Security (InfraSec) team. InfraSec protects the foundations of OpenAI’s research and production environments, spanning GPU supercomputing clusters, multi-cloud infrastructure, datacenters, networking, storage, and the critical services that power our frontier AI models. Our charter includes securing everything from bare-metal hardware and firmware, to Kubernetes clusters and service meshes, to data storage and access pathways for highly sensitive model weights and user data. As a principal engineer, you will set technical direction and drive execution on high-impact infrastructure security programs, partnering across various orgs at OpenAI to deliver durable controls that raise the security bar at OpenAI scale. In this role, you will: Own end-to-end security outcomes for one or more critical infrastructure areas, including multi-quarter strategy, roadmap, and delivery. Design and build security controls across diverse layers (e.g., physical hardware, firmware/BMC, OS, Kubernetes, networks, and CI/CD) to defend against sophisticated adversaries and insider threats. Lead cross-functional programs to deploy security enhancements and control changes across broad-scale infrastructure, balancing security guarantees with reliability and velocity. Take a generalist approach to building security controls, balancing a mix of security expertise and broad technical skillsets

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Security Software Engineer in the Enterprise Security team, you will advance Roblox's Enterprise Security strategy by building the systems and integrations that protect Roblox's corporate infrastructure. Where traditional security engineers evaluate and deploy vendor solutions, you will design and build production-grade security software - Identity and Access governance, policy enforcement engines, and security integrations that scale with Roblox's business. You'll partner with security professionals across InfoSec and work cross-functionally with Corporate Engineering, DevOps, and Product teams to drive security initiatives. You will: Build identity and access systems : Design, implement, and own integrations across Roblox's IAM ecosystem, including SSO federation, SCIM provisioning/deprovisioning pipelines, OAuth 2.0 authorization servers, and token lifecycle management. Lead security automation : Develop production-quality tools and services that enforce security policies at scale, replace manual workflows, and surface actionable signals Drive secure-by-design implementations : Partner with Corporate Engineering, DevOps, and product teams to embed security controls in

Our vision is to transform how the world uses information to enrich life for all. Join an inclusive team passionate about one thing: using their expertise in the relentless pursuit of innovation for customers and partners. The solutions we build help make everything from virtual reality experiences to breakthroughs in neural networks possible. We do it all while committing to integrity, sustainability, and giving back to our communities. Because doing so can fuel the very innovation we are pursuing. Main Responsibilities Define and own end-to-end security validation strategies across SSD product lifecycles, including development, qualification, release, and sustaining activities. Architect and maintain scalable security validation frameworks for current and next-generation SSD firmware platforms. Lead root cause analysis of security-related failures, customer escalations, qualification issues, and field escapes; drive corrective and preventive actions. Drive security test automation roadmaps, regression infrastructure, and validation tool development to improve coverage and efficiency. Collaborate with firmware architects, system architects, and development teams on secure design reviews, threat modeling, and security-focused code reviews. Assess and communicate security risks, validation coverage gaps, and mitigation strategies to stakeholders and leadership. Other Responsibilities Mentor engineers and provide technical leadership in security validation methodologies, test automation, and problem-solving approaches. Influence security validation standards, best practices, and qualification readiness across multiple SSD product generation