Senior Software Engineer, Platform

Company description Welcome to Our World We’ve been leading the charge in the affiliate industry from day one—establishing performance marketing and paving the way for future innovations. We're known for maintaining one of the largest, most reliable partnership platforms with impeccable, personalized service. Founded in Santa Barbara, California in 1998, CJ (formerly Commission Junction) stands as the most trusted name in performance marketing. We specialize in building partnerships between top brands and reputable publishers to drive revenue and business growth. CJ’s industry-leading solutions make us the platform of choice for over 3,800 global brands across sectors like retail, travel, finance, technology, and home services. As part of Publicis Groupe, our savvy data capabilities, cutting-edge tech, and strategic expertise facilitate genuine connections, allowing brands to reach consumers wherever they are. A Quick Peek at Affiliate Marketing Think back to your last online purchase. Did an influencer tip you off about a great product and offer a discount? Or perhaps you relied on a trusted review site to make your decision? Whatever path you took, affiliate publishers likely played a role by influencing, informing, or helping you find the best deal. CJ connects brands with these publishers, creating valuable resources for shoppers like you. Overview You must be work authorized in the United States without the need for employer sponsorship. This is a hybrid role requiring 3 days a week in a CJ office location. About CJ Engineering At CJ, we are passionate about software engineering. We build exciting software, with quality and maintainability in mind. We believe in common sense, simplicity, and efficiency. We practice critical thinking, challenge each other no matter the title, and believe in the wisdom of the team. That makes us Engineers and not just developers. Here are some of the principles that set CJ engineers apart. Engineering autonomy: Here, business decisions are made by business people, and technical decisions are made by technical people. Fullstack: Expect to be involved and to gain competence in every aspect of software engineering, from frontend, to database, to requirements analysis, to testing, to helping choose technologies. Clean, Maintainable code: Code is read more often than it is written, so we put in the effort to write it well in the first place. Pairing: The highest quality code is produced by close collaboration, so we pair by default. TDD: Quality is baked into our process through Test Driven Development. Ownership: Engineers own the full lifecycle of what they build—from design and implementation to deployment, monitoring, production support, and on‑call rotations. If we build it, we support it. Operational Excellence: We embrace Infrastructure as Code, CI/CD, automation, and observability to build reliable systems and deliver software safely, efficiently, and at scale. We believe in Agile values, and incremental development. We constantly experiment, retrospect, and adjust. We are committed to finding out how AI can amplify our productivity. We view AI as a force multiplier, not a replacement for good engineering. If this sounds exciting, we want to hear from you! As a Senior Software Engineer 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, and this role touches most of it. This is not just an infrastructure role - your value is in engineering judgment. You are a leader on the team: you own the reliability and operability of the platform, act as a critical reviewer of systems and changes, set standards, and mentor other engineers. We especially want someone with real depth in the systems below - we have made platform decisions we later had to reverse because the team lacked deep expertise in a component we owned, and that depth is exactly what this role brings. Responsibilities The Systems You Work On: EngExp owns the systems below. You'll own their reliability, be the critical reviewer of changes to them, and raise the team's depth in them: Observability & monitoring — Prometheus, Alertmanager, Grafana, and OpenTelemetry across every production region. This is not dashboard‑building: you own cardinality budgets and recording‑rule design, keep a production Prometheus healthy as it outgrows a single shard (federation / sharding / long‑term store strategy), and own Alertmanager HA and the blast radius of alert‑routing config. Deep Prometheus and Alertmanager expertise is a core requirement. Kubernetes & cloud infrastructure — multi‑region EKS clusters: upgrades, node group and Karpenter management, controller lifecycle, and add‑on / configuration management. Identify failure modes before they happen (subnet IP exhaustion, API server latency, ArgoCD reconciliation lag, Prometheus cardinality, Karpenter consolidation disruption). AWS networking — VPC design, subnet allocation and CIDR management, VPC peering, Transit Gateway, security groups, Route53, and NAT gateway topology across multiple accounts and regions, plus 24/7 networking alarms for all prod networking between clusters and squad resources. CI/CD & artifact management — GitLab administration (runner fleet, AMI updates, 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 (including cost alerts and reporting). Cost observability — OpenCost, EBS orphan cleanup, cost anomaly investigation, and rightsizing attribution across teams, so waste is attributable rather than shared overhead. Internal tools & delivery — the container image build pipeline and base image standards, code audit tooling, HedgeDoc, and the UI CDN (S3 + CloudFront), plus adopted applications with no other owner. What You'll Do: Own the reliability and operability of the systems above - focused on what is happening and why. Establish and enforce platform standards: RBAC, admission webhooks, resource limits, LimitRanges, policy-as-code. Manage infrastructure-as-code with Terraform across AWS accounts. Act as a high‑quality reviewer of infrastructure changes - Terraform, Kubernetes configs, CI/CD pipelines, observability config - catching subtle issues and long‑term risks before they ship. Turn recurring requests (ingress, DNS, service accounts) into self‑service workflows that are hard to misuse. Drive resolution of platform incidents with a focus on learning and lasting system improvement. Evaluate new patterns (Gateway API / Kgateway, claim‑based self‑service) on tradeoffs, not hype. Mentor less‑senior engineers and raise the team's depth in the components we own. 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 across accounts and regions) Terraform, AWS (IAM, EKS, S3, EBS) ArgoCD, GitLab CI/CD, Nexus (artifact registry), Docker, container image build pipelines Vault, OpenCost Gateway API / Kgateway Kubernetes controllers/operators (reconciliation patterns, restart safety) - Go experience is a plus, not required Qualifications What We Look For: 6+ years of experience in software and/or infrastructure engineering Bachelor's degree or equivalent experience Deep, hands‑on production experience operating Kubernetes and AWS at scale, across multiple accounts and regions Real operational depth in at least one system we own beyond the cluster - most importantly 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. Strong AWS networking judgment (VPC, peering, Transit Gateway, subnet/CIDR design) A track record as a critical reviewer - spotting subtle infrastructure issues and long‑term risks before they ship Experience leading technical work and mentoring engineers; can manage, clarify, and plan around uncertainty Effective communication and the ability to influence design in a product‑focused way Nice to Have: Prometheus long‑term storage / sharding (Thanos, Cortex, Mimir, or equivalent) run in production Experience owning a container image / base image pipeline Policy-as-code (Kyverno/ OPA) and admission webhook design Building claim‑based self‑service platform capabilities What Success Looks Like: Engineers can deploy and debug services without needing platform intervention The systems we own are understood deeply enough that we stop making decisions we have to reverse Production issues are understood quickly, not just reacted to Platform changes are intentional and low‑risk, and standards are clear and enforced Additional information This is a hybrid role requiring 3 days a week in office. CJ is the leader in Performance Marketing. We take pride in our innovative technology, comprehensive data solutions and our people. We equip our teams with advanced tools, training and career development opportunities all to provide modern solutions, strategies and support to deliver high quality results for our clients. We work in an enthusiastic, collaborative team setting that values outstanding performance. We're a community of creative and passionate problem solvers who go the distance to tackle the tough questions, think creatively, and drive resourceful growth, for our clients—and ourselves. We foster and embody an inclusive and collaborative culture where diverse perspectives are sought, relationships are valued, and people feel accepted with a sense of belonging in expressing themselves authentically. We pride ourselves in having a workplace environment that values both work and play. Why Our Workplace Stands Out Apart from offering competitive salaries, 401K matching, wellness programs, and comprehensive medical, dental, and vision coverage, we provide: Flexible time off without the hassle of accrual A generous number of paid holidays Company‑sponsored team‑building events An Employee Referral Program Annual recognition awards Hybrid work arrangements for optimal work‑life balance Parental bonding leave Backup care options for children and elders An employee discount program International SOS program for global support Business Resource Groups, where employees connect over shared interests to cultivate an engaging, inclusive environment …and those are just a few of our great perks! Come join us and see what makes our company a great place to work. If you require accommodation or assistance with the application or onboarding process specifically, please contact View email address on click.appcast.io. All your information will be kept confidential according to EEO guidelines. #LI-DT1 Compensation Range: USD $112,290.00 - USD $172,032.00/Annually. This is the pay range the Company believes it will pay for this position at the time of this posting. Consistent with applicable law, compensation will be determined based on the skills, qualifications, and experience of the applicant along with the requirements of the position, and the Company reserves the right to modify this pay range at any time. Temporary roles may be eligible to participate in our freelancer/temporary employee medical plan through a third‑party benefits administration system once certain criteria have been met. Temporary roles may also qualify for participation in our 401(k) plan after eligibility criteria have been met. For regular roles, the Company will offer medical coverage, dental, vision, disability, 401k, and paid time off. The Company anticipates the application deadline for this job posting will be 9/27/2026. #J-18808-Ljbffr Commission Junction Inc