Principal Security Engineer (Product & Business Enablement)

Mariner is seeking a Principal Security Engineer to serve as an embedded security partner to business, product, data, and technology teams. The role develops practical security architecture and reusable patterns across SaaS platforms, applications, APIs, data flows, and AI capabilities, enabling teams to deliver securely and efficiently.

Responsibilities:

• Assess end-to-end architectures spanning SaaS platforms, internally developed applications, APIs, integrations, data services, and AI; identify trust boundaries, sensitive data flows, and failure modes
• Facilitate architecture and threat reviews with delivery teams; document decisions and residual risk
• Own and maintain a library of secure-by-design patterns for SaaS adoption, APIs, integrations, data movement, secrets, credentials, authorization, and AI-enabled workflows
• Translate security requirements into practical designs that enable business outcomes—reducing reliance on late-stage reviews
• Serve as a primary security partner for product, enterprise architecture, data, and technology teams, engaging early in roadmaps and design
• Provide security expertise in vendor evaluations and SaaS selection in partnership with procurement and enterprise architecture
• Collaborate with Security Platform Engineering to convert security requirements and approved patterns into automated guardrails and self-service workflows
• Partner with Identity & Access and Infrastructure teams on authentication, authorization, posture management, and observability
• Provide technical security support for AI-enabled products and workflows, ensuring secure data boundaries and auditability
• Support the evolving enterprise data strategy, M&A activities, and technology onboarding with robust security architecture
• Enable business and technology teams via regular office hours, training, and embedded engagement; build security fluency and support sound decision-making

Requirements:

• Bachelor's degree in Computer Science, Engineering, Information Security, or related field (or equivalent practical experience)
• 10+ years of experience in security architecture, cloud/SaaS security, solutions architecture, software engineering, or SRE/DevOps, with at least 5 years in a dedicated security role
• Demonstrated track record securing distributed business systems with SaaS, APIs, integrations, identity, and third-party services
• Ability to rapidly analyze unfamiliar architectures, identify material risks, and translate findings into actionable designs
• Experience partnering with business, engineering, and product teams to shape secure solutions and make risk-aware decisions
• Evidence of pragmatic, business-aware security thinking—able to revise requirements to match business context, with clear rationale and tradeoffs
• Strong systems-thinking and security-architecture abilities across SaaS, APIs, integrations, data, cloud, and AI
• Ability to bridge business outcomes and technical controls—quickly and credibly
• Exceptional communication and facilitation skills; able to influence and build trust across business and engineering stakeholders
• Pragmatic approach to risk—focus on material threats and empowering the business
• Technical credibility to challenge designs, review APIs, and reason authentically about authentication and authorization
• Adaptability, curiosity, and comfort navigating rapidly evolving ecosystems
• Hands-on engineering or architecture background
• experience collaborating with business or product teams
• Experience shifting the perception of security from a business obstacle to an enabler
• Background in SaaS- and integration-rich environments with AI-enabled workflows
• Familiarity with data security concepts (classification, DLP, encryption, data governance, etc.)
• Experience in financial services, wealth management, regulated industries, or M&A technology integrations
• Security certifications (CISSP, CCSP, CSSLP, cloud security)