Principal Software Engineer – Identity & Access Management (Mexico)

Description

Sezzle (NASDAQ: SEZL) — the Minneapolis-headquartered Buy Now Pay Later fintech with ~400 employees and contractors, gross annual revenue above $450 million and net income over $133 million — is hiring a Principal Software Engineer to own and lead the evolution of authentication and authorization, working fully remotely from Mexico. Sezzle is investing in the next generation of its auth platform, centred on a purpose-built API auth gateway and a clean set of identity and access management services; you will own the technical vision, architecture and migration strategy for that transformation. Responsibilities include architecting scalable, highly-available auth services in Golang on AWS with RDS (MySQL/Postgres); leading phased zero-downtime migrations of auth traffic with rollback safety at every step; setting OAuth2/OIDC, token strategy (JWT, opaque, refresh), service-to-service auth (mTLS, workload identity) and fine-grained authorization standards (RBAC/ABAC/policy-as-code); partnering with Security and Compliance on fintech-grade regulatory requirements; on-call for owned services; and mentoring engineers. Requires 12+ years of professional software engineering experience, deep hands-on auth expertise, experience operating an API gateway or auth proxy at scale (Kong, Envoy, AWS API Gateway, Traefik or in-house), a proven large-scale service extraction or migration, strong Golang, and a Bachelor's in Computer Science. Sezzle explicitly requires demonstrated AI-forward engineering — active daily use of tooling such as Claude Code, Codex or Cursor, with practical opinions on where it helps and where it does not. The listing states: "This is a fully remote role. We believe the best engineers can do world-class work from anywhere, and we hire accordingly... no relocation or commute attached to it." Compensation: $6,000–$11,000 USD per month gross, negotiable on skills and experience. Note: the application requires eligible work authorisation in Mexico and university transcripts.

Required Skills