Senior Software Engineer, Backend

Responsibilities

• Define and evolve workload safety standards for Affirm’s Amazon EKS fleet, including resource settings, workload isolation, placement, disruption tolerance, and graceful termination.
• Own standards end to end through research, prototyping, early-adopter onboarding, self-service guidance, automation, and policy guardrails.
• Lead cross-team initiatives from design through fleet-wide rollout, mentor engineers, and maintain high standards for design, code review, and operational readiness.
• Troubleshoot workload and node lifecycle issues, including termination handling, pod disruption budgets, Karpenter timeouts, bin packing, and excess-capacity removal.
• Determine safe cluster operating limits and develop control-plane scaling patterns for bursty workloads.
• Analyze workload CPU, memory, disk, and network profiles to guide EC2 instance strategy and automate the analysis.
• Measure the effects of standards on availability, latency, risk, and cost to prioritize the roadmap.
• Participate in on-call for Kubernetes runtime issues and convert recurring failure patterns into systemic fixes.
• Collaborate with service, batch, ML workload, deployment, capacity, and SRE teams and keep current with Kubernetes best practices.

Requirements

• 5+ years of experience running Kubernetes in production at scale, ideally Amazon EKS across many clusters.
• Deep understanding of Kubernetes resource management and scheduling, including requests and limits, OOM behavior, CPU throttling, affinity and anti-affinity, taints and tolerations, and topology spread constraints.
• Strong knowledge of pod lifecycle and disruption management, including graceful termination, pod disruption budgets, and node draining.
• Experience enforcing configuration standards through admission control and policy-as-code, such as OPA Gatekeeper or Kyverno.
• Proficiency in Go or Python and experience building production infrastructure software such as Kubernetes controllers, operators, or admission webhooks.
• Strong production debugging skills and the ability to turn recurring incidents into systemic fixes.
• Experience leading technical initiatives across multiple teams, driving adoption of shared standards, and mentoring engineers.
• Experience quantifying infrastructure changes’ impact on availability, latency, and cost.
• Strong written communication skills for producing standards and guidance that teams can adopt independently.

Benefits

• Remote-first role open to candidates residing in specified Canadian provinces.
• All new hires are invited to an in-person onboarding experience, with occasional office work possible depending on the position.
• 100% subsidized medical coverage for employees and dependents, plus dental and vision coverage.
• Monthly technology, health, and wellness spending stipends.
• Flexible time off and generous holiday calendars.
• Employee stock purchase plan with a discounted opportunity to buy Affirm stock.