Principal Software Engineer (Authentication & Access)

Overview One Identity 's OneLogin is seeking a Principal Software Engineer to lead the architecture, correctness, and evolution of authentication and access systems across our platform. These systems are among the most security-critical and failure-sensitive areas of the product and require deep expertise in identity protocols, session management, and secure system design. As a Principal Engineer, you will operate with broad technical ownership—defining standards, guiding implementation, and resolving systemic issues across authentication flows, authorization models, and session behavior. You will work across teams to ensure that authentication systems are secure, reliable, and consistent, while evolving legacy implementations toward modern, scalable designs. While deeply focused on authentication and access, you will contribute broadly across the platform, applying this expertise to improve system design and reliability in adjacent areas. This is a hands-on role that includes system design, deep debugging of cross-service behavior, and driving modernization efforts in a complex distributed SaaS environment. You will also play a key role in mentoring engineers and raising the level of expertise in authentication and access across the organization. Responsibilities Own the correctness, security, and consistency of authentication and access systems across the platform • Define and evolve authentication flows, authorization models, and session lifecycle patterns • Ensure protocol correctness and consistency across protocols (SAML, OAuth 2.0, OpenID Connect, etc.) • Establish and drive adoption of consistent authentication and access patterns across teams, ensuring alignment with defined standards • Design and validate secure, state-machine-driven authentication workflows • Standardize handling of MFA, session behavior, and authentication edge cases • Identify and remediate legacy or inconsistent authentication implementations • Improve resilience and secure failure han