Principal Infrastructure Engineer

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

📋 Description

• Design, develop, manage, and scale the platform that powers Sezzle.

• Take ownership of intricate technical projects from architecture and prototyping to implementation, production deployment, and continuous operation.

• Recognize system limitations and apply infrastructure enhancements to accommodate increased traffic, data volume, and complex workloads.

• Create capacity models, conduct load and stress testing, and troubleshoot compute, networking, Kubernetes, and database bottlenecks.

• Architect robust AWS accounts, IAM, network, and service structures.

• Develop and manage the Kubernetes platform, focusing on lifecycle automation, workload isolation, resource allocation, autoscaling, upgrades, and deployment reliability.

• Scale and fine-tune Aurora RDS for MySQL and Postgres, addressing queries, indexes, connections, replication, failover, schema modifications, and migrations.

• Define and implement service-level objectives and error budgets; establish failure isolation, backpressure, load shedding, and safe retries.

• Engage in on-call rotations and take the lead in technical recovery during critical incidents and outages.

• Design, test, and document disaster recovery, backup, restore, and failover strategies.

• Create infrastructure-as-code and operational automation to reduce manual tasks.

• Enhance observability through metrics, logs, traces, dashboards, and actionable alerts.

• Execute safe infrastructure migrations with phased rollouts, validation, and rollback strategies.

• Increase cloud cost efficiency through resource right-sizing, utilization, autoscaling, and storage optimization.

• Develop and assess AI-assisted tools for incident investigation, runbooks, anomaly analysis, and repetitive tasks.

• Draft architecture proposals, assess technology trade-offs, review shared infrastructure modifications, and document system functionality and failures.

• Report to engineering leadership and work collaboratively with application engineers, Security, and Compliance.

⛳️ Requirements

• Bachelor's degree in Computer Science or a related technical field (required).

• Over 12 years of experience in infrastructure, platform, site reliability, software development, or related engineering fields.

• Extensive production knowledge of AWS, encompassing compute, IAM, multi-account architectures, networking, VPC design, and private connectivity.

• Significant expertise in Kubernetes; EKS experience is highly preferred.

• Deep knowledge of RDS/Aurora for MySQL and/or Postgres at scale.

• Proven track record of delivering infrastructure scaling enhancements personally.

• Strong coding and automation capabilities using Golang, Python, or similar programming languages.

• Experience with infrastructure-as-code using Terraform or equivalent.

• Solid understanding of systems fundamentals in Linux, networking, DNS, TLS, storage, concurrency, and distributed system failure modes.

• Experience in operating 24/7 high-availability platforms with hands-on incident response and postmortem analysis.

• Willingness to participate in on-call rotations.

• Experience in implementing and testing disaster recovery plans against established recovery objectives.

• Practical background in observability, load testing, capacity planning, and safe CI/CD practices.

• Active engagement with AI tools in engineering or operations.

• Ability to navigate ambiguous technical challenges through production delivery and collaborate across engineering teams.

• Preferred: experience in fintech, payments, or banking; knowledge of multi-region architectures; chaos engineering; familiarity with Prometheus, Grafana, Loki, Tempo; internal platform capabilities; and AI-assisted operational automation.

🏝️ Benefits

• Competitive gross monthly compensation.

• Opportunity to engage with innovative fintech, payment, and retail technologies.

• Remote work availability (job tagged #Li-remote).

• Collaboration with international teams and various technical domains.

• Exposure to AI-assisted infrastructure and SRE tools.

• Open-source-focused technology environment.

• A vibrant employee culture that includes musicians, yogis, cyclists, chefs, golfers, dog lovers, and rock climbers.