Remote Principal Software Engineer, IAM & API Gateway

Sezzle; Argentina; On-site; ARS 99,666,587 - 182,722,076; Full time

Job summary

Sezzle is seeking a Principal Software Engineer to own and lead the evolution of authentication and authorization. You will guide the API gateway and identity services, shaping the technical vision and migration strategy across teams.

In this backend-focused role, you will mentor engineers, establish secure-by-default patterns, drive observability and CI/CD improvements, and apply AI-assisted development to accelerate secure solutions.

Qualifications

• 12+ years of professional software engineering with backend focus.
• Extensive experience in authentication and authorization systems (OAuth2, OpenID Connect, SAML, JWT).
• Proven track record leading large-scale service migrations with zero or minimal customer impact.
• Strong Golang proficiency and RESTful API design.
• Experience with SQL-based databases (MySQL, PostgreSQL) and high-performance queries.
• Experience with API gateways or auth proxies (Kong, Envoy, AWS API Gateway).
• Bachelor’s degree in Computer Science or a related field.

Responsibilities

• Own the technical vision and roadmap for Sezzle’s authentication and authorization platform.
• Architect and build scalable, highly-available auth services and gateway components.
• Design phased, zero-downtime migrations with rollback and safety mechanisms.
• Collaborate with Security, Compliance, and Product to meet fintech-grade requirements.
• Mentor engineers and promote secure-by-default patterns and CI/CD discipline.
• Lead incident response on the auth-critical path and contribute to postmortems.

Job description

Sezzle is seeking a Principal Software Engineer to own and lead the evolution of authentication and authorization. You will guide the API gateway and identity services, shaping the technical vision and migration strategy across teams.

In this backend-focused role, you will mentor engineers, establish secure-by-default patterns, drive observability and CI/CD improvements, and apply AI-assisted development to accelerate secure solutions.