Senior Authentication & Access Platform Architect

One Identity, LLC; United Kingdom; Remote; GBP 90,000 - 130,000; Full time

Job summary

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. This hands-on role includes system design and mentoring engineers in a complex distributed SaaS environment.

The ideal candidate will own authentication flows and security across services, guide modernization efforts, and ensure secure, scalable designs while maintaining backwards compatibility.

Qualifications

• 8+ years of software engineering experience with ownership of critical production systems, including authentication and access services.
• Strong backend development experience in Ruby/Node.js or similar.
• Experience building and operating authentication, authorization, and API-based services in distributed environments.
• Solid understanding of REST APIs, service contracts, and software design principles.

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 across SAML, OAuth 2.0, OpenID Connect, etc.
• Establish and drive adoption of consistent authentication and access patterns across teams.
• 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 handling across authentication flows.
• Guide the evolution and modernization of authentication systems while maintaining backwards compatibility.

Skills

Identity protocols

Backend development

Ruby/Node.js

APIs

REST APIs

Distributed systems

Security engineering

PKI

CI/CD

Observability

On-call

AI tools

Tools

AWS

Kubernetes

CI/CD tooling

Job description

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. This hands-on role includes system design and mentoring engineers in a complex distributed SaaS environment.

The ideal candidate will own authentication flows and security across services, guide modernization efforts, and ensure secure, scalable designs while maintaining backwards compatibility.