Principal Software Engineer – Identity & Access Management

This is a fully remote position, open to applicants in Argentina.

📋 Description

• Take ownership of the technical vision and roadmap for Sezzle’s authentication and authorization platform, which includes an API authentication gateway and identity services.

• Design, architect, and develop scalable and highly available authentication services and gateway components, primarily utilizing Golang, AWS, RDS, and distributed patterns.

• Lead the design and execution of phased, zero-downtime migrations with rollback and safety mechanisms in place.

• Set standards for authentication and authorization, covering OAuth2/OIDC, JWT, opaque and refresh tokens, mTLS, workload identity, RBAC, ABAC, and policy engines.

• Ensure consistency and scalability across distributed microservices while upholding performance, reliability, and edge-gateway latency requirements.

• Collaborate with Security and Compliance teams to meet fintech-grade security and regulatory requirements.

• Implement engineering best practices for observability, security, and CI/CD processes.

• Engage in on-call rotations and take the lead in incident response and postmortems.

• Mentor engineers, fostering a culture of learning, innovation, and operational excellence.

• Work collaboratively across functions to translate business objectives into technical roadmaps and achieve results.

• Assist in establishing effective AI-tooling practices for security-sensitive systems.

⛳️ Requirements

• Over 12 years of professional software engineering experience, with a strong focus on backend development.

• Successfully deployed significant changes to a production application within the last 30 days.

• Extensive hands-on experience with authentication and authorization systems, including OAuth2, OpenID Connect, SAML, JWT, session-based authentication, token lifecycle management, RBAC, ABAC, and policy-as-code.

• Experience in designing, building, or operating an API gateway or authentication proxy at scale.

• Proven ability to lead large-scale service extraction or migration projects with zero or minimal customer impact.

• High proficiency in Golang and experience in building and maintaining RESTful APIs.

• Expertise in SQL-based relational databases, such as MySQL and PostgreSQL, including query and schema optimization at scale.

• Familiarity with distributed systems patterns, including transactional outbox, event-driven architecture, and queues.

• Capacity to influence decisions and lead complex technical initiatives across teams.

• Demonstrated current use of AI tools like Claude Code, Codex, Cursor, or custom LLM integrations.

• Bachelor’s degree in Computer Science or a related technical field (required).

• Preferred: experience with identity platforms and standards such as Keycloak, Auth0, Okta, Ory, or in-house IdPs.

• Preferred: knowledge of service mesh and edge technologies like Envoy, Istio, mTLS, rate limiting, and WAF integration.

• Preferred: understanding of threat modeling, secure design reviews, and knowledge of authentication attack vectors.

• Preferred: familiarity with observability tools such as Prometheus, Grafana, Datadog, or New Relic.

• Preferred: experience with AWS cloud infrastructure, particularly Aurora RDS for MySQL and PostgreSQL.

• Preferred: background in fintech, payments, BNPL, or consumer lending, including familiarity with PCI-DSS or SOC 2.

• Preferred: experience with CI/CD pipelines and containerized microservices using Docker and Kubernetes.

• Preferred: experience with commercial APIs and platform infrastructure in high-growth environments.

• Preferred: expertise in technical leadership, reliability enhancement, and scaling engineering organizations.

🏝️ Benefits

• Fully remote work opportunities.

• No need for relocation or commuting.

• Competitive salary packages.

• Principal-level scope and ownership of projects.

• Opportunities for career advancement.

• Access to AI-assisted development tools and workflows.

• Exposure to innovative fintech and retail technologies.

• A culture that promotes learning, innovation, and operational excellence.