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# Software Engineer 3, Platform

- **Company:** Commission Junction LLC
- **Location:** Agoura Hills, CA, United States
- **Experience:** Experienced
- **Salary:** $88,540.0
- **Contract:** Temporary contract
- **Skills:** Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Amazon S3, ARM Architecture, Cloud Computing, Configuration Management, Continuous Integration, Shard (Database Architecture), Software Debugging, Domain Name System (DNS), Monitoring of Systems, Identity and Access Management, Subnetting, Key Management, Cisco Nexus Switches, Octopus Deploy, Peering, Role-Based Access Control, Prometheus, Policy as Code, Grafana, Amazon Virtual Private Cloud (VPC), Gitlab, Gitlab-ci, Kubernetes, Route53, Terraform, Webhooks, Docker
- **Published:** October 12, 2026
- **Apply:** https://www.juju.com/job/1_publicisgroupe2-168579

## About the Role

across accounts and regions) + Terraform, AWS (IAM, EKS, S3, EBS) + ArgoCD, GitLab CI/CD, Nexus (artifact registry), Docker, container image build pipelines + Vault, OpenCost + Kubernetes controllers/operators (reconciliation patterns, restart safety) - Go experience is a plus, not required **Qualifications** What We Look For: + 3+ years of experience in software or infrastructure engineering + Bachelor's degree or equivalent experience + Hands-on production experience with Kubernetes and at least one major cloud (AWS preferred) + Real operational depth in at least one system we own beyond the cluster - most valuably the observability stack (Prometheus/Alertmanager at scale), but AWS networking, Vault, or artifact/CI infrastructure also count.
We are filtering for people who have run these systems, not just used them. + Comfortable owning infrastructure-as-code (Terraform) and CI/CD pipelines + Can reason about tradeoffs and communicate the pros and cons of multiple approaches + Effective communication; thrives in a collaborative, pair-friendly team culture Nice to Have: + AWS networking depth (Transit Gateway, multi-account topology) + Prometheus long-term storage / sharding (Thanos, Cortex, Mimir, or equivalent) + Kubernetes controllers/operators - Go experience is a plus, not required + Policy-as-code (Kyverno / OPA) What Success Looks Like: + You own platform components independently and ship changes that are intentional and low-risk + The systems you own are understood deeply enough that we stop making decisions we have to reverse + Production issues are understood quickly because of the observability and instincts you bring + Engineers can deploy and debug services with less

## Description

As a Software Engineer 3 on the Engineering Experience (EngExp) platform team, you help run and evolve the platform that powers CJ's production systems across multiple AWS regions. "Platform" here is broad - it is the Kubernetes clusters, but also the observability stack every squad depends on, the CI/CD and artifact infrastructure their builds run through, the AWS networking that connects them, the secrets and access systems that gate them, and the cost visibility that keeps them accountable.
EngExp owns all of it.
This is not just an infrastructure role - your value is in engineering judgment: how you evaluate systems, detect risk, and make decisions under uncertainty.
You'll own meaningful pieces of these systems independently and drive changes from design through production.
We want real depth in the systems below, not just familiarity with the tool names. **Responsibilities** What systems you will work on: + Observability & monitoring - Prometheus, Alertmanager, Grafana, and OpenTelemetry across production regions.
This is not dashboard-building: you'll own cardinality budgets and recording-rule design, keep a production Prometheus healthy as it outgrows a single shard (federation / sharding / long-term store), and understand Alertmanager HA and the blast radius of alert-routing config.
Deep Prometheus and Alertmanager knowledge is a core requirement. + Kubernetes & cloud infrastructure - multi-region EKS clusters: upgrades, node group and Karpenter management, controller lifecycle, and add-on / configuration management.
Spot failure modes before they happen (subnet IP exhaustion, API server latency, ArgoCD reconciliation lag, Prometheus cardinality, Karpenter consolidation disruption). + AWS networking - VPC and subnet design, CIDR management, VPC peering, Route53, security groups, and NAT gateway topology across accounts and regions, plus the 24/7 networking alarms for prod networking between clusters and squad resources. + CI/CD & artifact management - GitLab administration (runner fleet, cache, access - not just pipeline authoring), GitOps delivery through ArgoCD, and the Nexus artifact repository including its storage lifecycle as it grows. + Access & identity - Vault secrets management, IAM roles and service accounts for apps in clusters, cluster permission management for audit compliance, and AI model access management.
Turn recurring access requests into self-service workflows that are hard to misuse. + Cost observability - OpenCost, EBS orphan cleanup, cost anomaly investigation, and rightsizing attribution across teams.
What You'll Do: + Own and evolve meaningful pieces of the systems above - with a focus on what is happening and why + Manage infrastructure-as-code with Terraform across AWS accounts + Build and maintain GitLab CI/CD pipelines and GitOps delivery (ArgoCD) + Help enforce platform standards: RBAC, admission webhooks, resource limits, LimitRanges + Turn recurring requests (ingress, DNS, service accounts) into self-service workflows + Respond to and help drive resolution of platform incidents, focused on learning and system improvement + Act as a reviewer of infrastructure changes - Terraform, Kubernetes configs, observability config Technologies We Use: + Kubernetes / EKS (multi-cluster, multi-region), Karpenter, cert-manager, external-dns + Prometheus, Alertmanager, Grafana, OpenTelemetry (and long-term storage / sharding for Prometheus) + AWS networking (VPC, VPC peering, Transit Gateway, Route53, NAT Gateway, security groups, subnet/CIDR design