Senior Software Engineer, Backend (Workload Safety)Active$153K–$213K

The opportunity

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most.

What you'll do

  • Define and evolve workload safety standards for Affirm's EKS fleet, such as: CPU and memory settings, workload isolation and placement, tolerance for disruption, graceful termination to name a few

  • Own each standard end to end: research and prototyping, white-glove onboarding for early adopters, self-service guidance for everyone else, and automation and policy guardrails that keep every workload compliant from day one

  • Lead cross-team initiatives from design through fleet-wide rollout, mentor: other engineers, and set a high bar for design, code review, and operational readiness

  • Isolate workloads by criticality and resource profile so one misbehaving: workload cannot degrade critical paths such as checkout

  • Fix stuck workloads and node lifecycle problems, such as pods that ignore: termination signals, pod disruption budgets that block node cycling, and Karpenter timeouts that prevent bin packing and the removal of excess capacity

  • Determine the safe operating limits of each cluster (pod count, node count,: API server request volume), keep clusters within them, and develop control plane scaling patterns for bursty workloads such as scheduled batch jobs and large deployments

What they're looking for

  • Analyze workload resource profiles across the fleet (CPU, memory, disk,: network) to guide EC2 instance type strategy, and automate that analysis as workloads change
  • Measure each standard's impact on availability, latency, risk, and cost, and: use the results to prioritize the roadmap
  • Participate in on-call for Kubernetes runtime issues across the fleet, and: turn recurring failure patterns into roadmap items
  • Work closely with the teams that run services, batch jobs, and ML workloads: on EKS, and with the deployment, capacity, and SRE teams