Principal Infrastructure Engineer

Sezzle is seeking an exceptional Principal Infrastructure Engineer to design, build, operate, and scale the platform that powers our fintech solutions. You will focus on solving complex infrastructure challenges, including increasing throughput, reducing latency, removing capacity bottlenecks, and strengthening system resilience as our business continues to grow.

Key responsibilities

• Own the technical architecture and evolution of core infrastructure, identifying system limits and implementing changes to support increasing traffic.
• Engineer for scale and performance by building capacity models, running load tests, and diagnosing bottlenecks across compute, networking, and databases.
• Build and operate the Kubernetes platform, improving cluster architecture, lifecycle automation, and deployment reliability.
• Scale and optimize Aurora RDS for MySQL and Postgres, tuning queries and managing replication to ensure high availability.
• Participate in on-call rotations and lead technical recovery during serious incidents, using evidence-based triage to implement lasting fixes.
• Develop infrastructure-as-code and operational automation to eliminate manual toil and ensure reproducible, testable systems.

Requirements

• Bachelor's degree in Computer Science or a related technical field.
• 12+ years of experience in infrastructure, platform, or site reliability engineering with deep expertise in production environments.
• Strong proficiency with AWS, Kubernetes, and relational databases like Aurora RDS (MySQL/Postgres).
• Proven track record of delivering infrastructure scaling improvements and managing high-availability platforms.
• Strong coding skills in Golang or Python, alongside experience with Terraform or similar infrastructure-as-code tools.
• Ability to debug complex systems across infrastructure and application boundaries.

What we offer

• The opportunity to work on cutting-edge fintech infrastructure at a global scale.
• A culture that values high standards, calculated risk-taking, and technical excellence.
• Collaboration with a purpose-driven team of innovators in a fully remote environment.