Software Engineer II - Identity & Access Management

ABOUT THE ROLE We are seeking a highly skilled Software Engineer II to join our Identity & Access Management (IAM) team at Klaviyo. As a key member of our Core Infrastructure – Identity & Organizations (Core IO) pillar, you will play a critical role in shaping Klaviyo's centralized authentication and authorization platform. This is an exciting opportunity to design and build services that power login, SSO, MFA, SCIM, internal service auth, and external API auth, and to transform Klaviyo's identity stack into a unified, enterprise-grade platform. WHAT YOU'LL DO As a Software Engineer II on the IAM team, you will be responsible for owning features end-to-end across design, implementation, rollout, and observability for core authN/Z capabilities. This will include: - Designing and implementing login flows, MFA, SSO enhancements, SCIM, sessions, and role/permission enforcement - Contributing to the extraction of authentication and authorization paths from the legacy monolith into dedicated micro services - Building and maintaining shared SDKs and contracts that enable internal teams to adopt IAM services quickly - Collaborating with the Organizations & Accounts team to support org-scoped identity, multi-account SSO, and flexible org/account models - Partnering with Platform Integrity & Protection, Security, and Compliance to ensure IAM is a strong foundation for account security and anti-abuse controls - Improving the reliability and performance of IAM services through instrumentation, debugging, and on-call rotations - Defining and refining standards for authentication and authorization across the platform APIs, error semantics, audit logging, and integration patterns WHAT YOU'LL NEED To be successful in this role, you should have: - 2-5+ years of professional software engineering experience, including building and operating backend or full-stack services in production - Strong fundamentals and debugging skills, including reasoning about data models, API design, concurrency, and failure modes - Experience with authentication, authorization, and account security problems, including MFA, SSO, SCIM, OAuth, and roles/permissions - A platform/infra mindset, including a desire to build reusable services and tools that other engineers rely on - Ownership and collaboration skills, including taking responsibility for outcomes and communicating trade-offs clearly in design docs and PRs WHY REMOTE As a remote employee at Klaviyo, you will have the flexibility to work from anywhere and enjoy a range of benefits, including: - A competitive salary and equity package - A comprehensive health plan - Parental leave and education stipend - Life insurance and equipment stipend - Flexible schedule and remote work arrangement - Opportunities for professional growth and development BENEFITS - Competitive salary and equity package - Comprehensive health plan - Parental leave and education stipend - Life insurance and equipment stipend - Flexible schedule and remote work arrangement