Calling the bold.

Calling the bold.

Uncork-backed companies are hiring explorers, builders, and operators ready to help chart new territory.

Uncork-backed companies are hiring explorers, builders, and operators ready to help chart new territory.

Principal Site Reliability Engineer

ZEFR

ZEFR

Administration, Software Engineering
marina del rey, ca, usa
USD 210k-235k / year
Posted on Jan 27, 2026

Location

Marina del Rey, CA

Employment Type

Full time

Location Type

Hybrid

Department

TechnologyEngineering

What we do:

Zefr is the leading global technology company enabling responsible marketing in walled garden social environments. Zefr’s solutions empower brands to manage their content adjacency on scaled platforms such as YouTube, Meta, TikTok, and Snap, in accordance with industry standard frameworks. Through its patented AI technology, Zefr offers brands and agencies more accurate and transparent solutions for social walled gardens. The company is headquartered in Los Angeles, California, with additional locations across the globe.

What you’ll do:
As a Principal Site Reliability Engineer at Zefr, you'll serve as a technical leader and subject matter expert, helping define the technical vision and shape the direction of our reliability practices across the organization.

You'll leverage deep expertise in observability, core SRE principles, cloud infrastructure, CI/CD and DevSecOps to solve our most complex challenges and set the standard for engineering excellence.

This role requires a blend of hands-on technical expertise and strategic thinking. You'll drive cross-functional initiatives, mentor engineers across teams, and partner with leadership to ensure our AI-powered platform is robust, efficient, and scalable.

We’re looking for someone to combine their technical expertise with strong leadership and a passion for continuous improvement and innovation. Zefr wants a candidate that champions reliability as a product feature, and can translate complex technical concepts into strategy. This is a role where you'll shape how we build and operate systems at scale.

  • Support and build systems and tools that enable other engineers to generate, deploy, and manage product features and models both quickly and safely.

  • Deploy and support a multi-cloud, micro-service architecture, including infrastructure tailored for ML workloads, deployed via Github Actions, ArgoCD & Kubernetes.

  • Collaborate with other engineers to architect secure, resilient, scalable, and cost-efficient applications and ML systems/pipelines in AWS and GCP.

  • Foster and push our DevOps culture and philosophy by encouraging continuous improvement across all engineering teams.

  • Proactively maintain the health of production environments, including monitoring application performance and resource utilization.

  • Participate in 24/7 on-call rotation, respond to system performance issues and outages.

  • Debug code at the application and infrastructure level.

  • Mature our CI/CD workflows and release process.

  • Maintains a forward-thinking approach, actively researching and proposing new solutions.

  • Propose and review Engineering Request for Comments (RFC) to drive Engineering architecture and practices.

Technology Stack at Zefr:

Core Infrastructure & Cloud Platforms:

  • Cloud Providers: Google Cloud Platform (primary), Amazon Web Services Infrastructure as Code (IaC): Terraform, Terragrunt

  • Containerization & Orchestration: Docker, Kubernetes (experience with GKE and/or EKS expected), Helm, Kustomize

  • Service Mesh: Istio

CI/CD & Automation:

  • CI/CD Pipelines: GitHub Actions

  • GitOps / Continuous Delivery: Argo CD

  • Primary Scripting/Automation Language: Python

Observability & Monitoring:

  • Monitoring & Alerting: Prometheus, Chronosphere, Pagerduty

  • Telemetry Standards: OpenTelemetry

Application & Data Ecosystem (Supporting):

  • Application Languages/Frameworks: Python, FastAPI, Flask, Node.js, React

  • Data Streaming: Apache Kafka

  • Data Processing/Transformation: Pandas, DBT

  • Workflow Orchestration: Apache Airflow, Ray

Data Stores & Databases:

  • Relational Databases: PostgreSQL (including managed versions like AWS Aurora, GCP Cloud SQL)

  • NoSQL Databases: DynamoDB

  • Search Databases: OpenSearch

  • Vector Databases: Qdrant

  • Caching: Redis

  • Data Warehousing: Snowflake

What we’re looking for:

  • 10+ year job history designing, managing, deploying, and supporting Cloud Infrastructure in a production environment using major public cloud providers (GCP experience a huge bonus)

  • Experience in Advertising or AdTech

  • Demonstrated technical leadership experience; including mentoring engineers, driving cross-functional projects, and influencing architectural decisions at an organizational level.

  • Knowledge of GitOps including an understanding of modern CI/CD pipelines, techniques and technologies (Github Actions, GitLab, CircleCI, Argo CD, Flux)

  • Advanced Proficiency with IaC and configuration management tools (Terraform, Terragrunt, OpenTofu, Crossplane, Pulumi)

  • Deep production experience architecting, managing, deploying, and supporting container based workloads into Kubernetes clusters

  • Proven track record of building and scaling reliability practices, including SLO/SLI frameworks, incident management, and capacity planning.

  • Heavy Production experience with observability platforms and practices (Prometheus, Grafana, Chronosphere, Datadog, OpenTelemetry); ability to design monitoring strategies for complex distributed systems.

  • Strong knowledge of cloud networking (Mesh, NAT, Load Balancers, API Gateways, proxies, etc), cloud security, and cost optimization strategies.

  • Exceptional written and verbal communication skills; ability to translate complex technical concepts for diverse audiences and build consensus across teams.

  • Experience authoring technical strategy documents, RFCs, and architectural proposals.

Benefits (for US based employees):

  • Flexible PTO

  • Medical, dental, and vision insurance with FSA options

  • Company-paid life insurance

  • Paid parental leave

  • 401(k) with company match

  • Professional development opportunities

  • 13 paid holidays off

  • Summer Fridays (we leave early)

  • In-office, hybrid, and fully-remote work options available

  • In-office lunches and lots of free food

  • Optional in-person and virtual events (we like to celebrate!)

Compensation (for US based employees):

The anticipated salary for this position is between $210,000 and $235,000. Within the range, individual pay is determined by factors such as job-related skills, experience, and relevant education or training. If your compensation expectations fall outside of this range, it may still be worth having a conversation.

Zefr is an equal opportunity employer that embraces diversity and inclusion in the workplace. We are committed to building a team that represents a variety of backgrounds, skills, and perspectives because we know this only makes us better. We strongly encourage women, persons of color, LGBTQIA+ individuals, persons with disabilities, members of ethnic minorities, foreign-born residents, and veterans to apply even if you do not meet 100% of the qualifications.