Principal Software Engineer – Identity & Access Management

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

📋 Description

• Take charge of the technical vision and strategy for Sezzle’s authentication and authorization platform, which includes a dedicated API authentication gateway and supporting identity services.

• Architect, design, and develop scalable and highly available authentication services and gateway components primarily using Golang, AWS, RDS, and distributed patterns.

• Design and oversee phased migrations of authentication traffic and functionality with zero downtime, incorporating rollback and safety mechanisms.

• Establish and enhance authentication and authorization standards, encompassing OAuth2/OIDC, token strategies, service-to-service authentication, and fine-grained authorization models.

• Ensure consistency and scalability across distributed microservices while maintaining performance, reliability, and latency budgets for an edge gateway.

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

• Set engineering best practices for observability, security, and continuous integration/continuous deployment (CI/CD).

• Participate in the on-call rotation and lead incident response and post-incident reviews.

• Mentor engineers and promote learning, innovation, and operational excellence.

• Work cross-functionally to convert business objectives into technical roadmaps and achieve results.

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

⛳️ Requirements

• Over 12 years of professional software engineering experience, with substantial backend expertise.

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

• Extensive hands-on knowledge of 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 managing an API gateway or authentication proxy at scale.

• Proven track record of leading large-scale service extraction or migration with little to no customer impact.

• Strong expertise in Golang and experience in building and maintaining RESTful APIs.

• Proficient in SQL-based RDBMS, such as MySQL and PostgreSQL, including schema and query performance optimization.

• Knowledge of distributed systems design patterns, including transactional outbox, event-driven architecture, and queues.

• Ability to propose ideas, influence decisions, and spearhead complex technical initiatives across teams.

• Demonstrated recent use of AI tooling, such as Claude Code, Codex, Cursor, or custom LLM integrations.

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

• Preferred: experience with identity platforms and standards implementations, service mesh and edge technologies, threat modeling, observability tools, AWS infrastructure, fintech/payments/BNPL/consumer lending, PCI-DSS/SOC 2, CI/CD, Docker, Kubernetes, commercial APIs, and platform infrastructure.

🏝️ Benefits

• Fully remote work.

• No need for relocation or commuting.

• Principal-level scope and ownership.

• Competitive salary.

• Opportunities for career advancement.

• AI-assisted development tools are standard in the development process.

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