Senior Software Engineer - Identity and Access Management

At Klaviyo, we value the different backgrounds, experiences, and perspectives that each Klaviyo brings to work. If you are close, but not an exact match, we hope you will still apply.

About the team

Identity and Access Management (IAM) controls how people, services, integrations, and AI agents access Klaviyo.

We build authentication and authorization for users, agents, and machines that access the Klaviyo platform.

This is a chance to solve hard identity problems that affect nearly every part of our product.

How you will make an impact

As a Senior Software Engineer, you will lead complex projects across several components while staying hands-on with the software. You will:

• Lead business-critical projects from design through launch and long-term operation.
• Build secure, reliable services for authentication, authorization, delegation, auditing, and revocation.
• Break ambiguous problems into clear work that several engineers can deliver together.
• Own the customer impact, reliability, and technical quality of your work in production.
• Improve the architecture of your area as scale, security, and product needs change.
• Define and maintain SLOs for the systems that you own.
• Partner with Security, Product, Platform, and product engineering teams.
• Create reusable patterns that make IAM easier and safer for other teams to adopt.
• Mentor engineers and help project contributors succeed.
• Apply new engineering and AI tools responsibly, then share what you learn with the team.
• Take on important unowned work that helps the team move faster.

Who you are

• You have 7+ years of experience building and operating production software.
• You have hands-on experience developing production services in Go or Python.
• You have experience with authentication, authorization, identity, or related security systems.
• You have built networking systems, API gateways, APIs, or SDKs.
• You have led complex projects that spanned multiple engineers and several months.
• You take end-to-end ownership and stay with your work after launch.
• You communicate clearly, work well across teams, and make practical technical decisions.
• You mentor other engineers and raise the quality bar through feedback and example.
• You balance long-term improvements with steady customer delivery.

Nice to have

• Experience with auth or policy systems.
• Experience building secure platforms used by other engineering teams.
• Experience with AWS, Terraform, Kubernetes, React, or Django.
• Experience with enterprise security, auditability, data residency, or compliance needs.

You do not need to know every part of our stack on day one. We care most about strong judgment, ownership, and care for the customer experience.