About the Company
Sezzle is a fintech company that provides interest-free installment plans, revolutionizing the shopping experience. We are building an innovative team to shape the future of fintech and retail.
About the Role
We are seeking a Principal Software Engineer to own and lead the evolution of authentication and authorization at Sezzle. You will own the technical vision, architecture, and migration strategy for our authentication platform, including a purpose-built API auth gateway and identity services.
Key Responsibilities
- Own the technical vision and roadmap for Sezzle's authentication and authorization platform.
- Architect, design, and build scalable, highly-available auth services and gateway components primarily in Golang, leveraging AWS, RDS (MySQL/Postgres), and modern distributed patterns.
- Design and lead phased, zero-downtime migrations of auth traffic and functionality.
- Establish and evolve authentication and authorization standards: OAuth2/OIDC flows, token strategy (JWT, opaque, refresh), service-to-service auth (mTLS, workload identity), and fine-grained authorization models (RBAC/ABAC/policy engines).
- Drive consistency and scalability across a distributed microservices architecture.
- Partner with Security and Compliance to ensure fintech-grade security and regulatory requirements.
- Establish and evolve engineering best practices for observability, security, and CI/CD.
- Participate in on-call rotation and lead incident response.
- Mentor engineers and champion a culture of learning and innovation.
Requirements
- 12+ years of professional software engineering experience, including significant backend experience.
- Deep, hands-on expertise in authentication and authorization systems: OAuth2, OpenID Connect, SAML, JWT, session-based auth, token lifecycle management, RBAC, ABAC, policy-as-code.
- Experience designing, building, or operating an API gateway or auth proxy at scale (e.g., Kong, Envoy, AWS API Gateway, Traefik).
- Proven track record leading large-scale service extraction or migration.
- Strong proficiency in Golang and RESTful APIs.
- Expertise with SQL-based RDBMS (MySQL, PostgreSQL).
Conditions
- Fully remote role.
- Competitive compensation range: $6,000 - $11,000 per month (Gross in USD), negotiable based on experience.