Principal Infra Engineer: Scale, Reliability & Cloud

sezzle; Poland; On-site; PLN 524,000 - 873,000; Full time

Job summary

Sezzle is seeking a Principal Infrastructure Engineer to design, build, operate, and scale the platform powering Sezzle. You will tackle the hardest infra problems: increasing throughput, reducing latency, removing bottlenecks, strengthening resilience, and automating production operations.

The role requires ownership from architecture to production rollout and ongoing operation in a cloud-first environment.

Responsibilities

• Own the technical architecture and evolution of core infrastructure to support increasing traffic and workload complexity.
• Connect business workflows to system improvements; trace impact across apps and data, partnering across teams.
• Engineer for scale and performance; build capacity models, run tests, diagnose bottlenecks and validate improvements.
• Design and build AWS infrastructure with IAM, networking, quotas, fault isolation, and multi-AZ/multi-region support.
• Build and operate the Kubernetes platform: cluster architecture, automation, autoscaling, upgrades.
• Tune Aurora RDS for MySQL and Postgres; optimize queries, connections, and replication.

Job description

Sezzle is seeking a Principal Infrastructure Engineer to design, build, operate, and scale the platform powering Sezzle. You will tackle the hardest infra problems: increasing throughput, reducing latency, removing bottlenecks, strengthening resilience, and automating production operations.

The role requires ownership from architecture to production rollout and ongoing operation in a cloud-first environment.