Senior ML Engineer - AdTech Real-Time Optimization (Remote)

Sigma Software; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

Sigma Software is seeking a Senior Machine Learning Engineer to build predictive models for a large programmatic advertising platform. You will design real-time scoring, ranking, and optimization components, and own end-to-end model lifecycles.

The role emphasizes production-grade ML systems, Kubernetes and Docker, MLflow/Kubeflow, and scalable training pipelines. Remote work with cross-team collaboration across distributed engineers.

Qualifications

• 6+ years of combined commercial experience in Data Science and ML Engineering.
• Strong production experience with machine learning systems delivering measurable business impact.
• Hands-on experience with gradient-boosted trees (XGBoost/LightGBM/CatBoost).
• Proficiency in Python and SQL for production-grade ML.
• Experience with ML orchestration and model registry management.
• Familiarity with Kubernetes and Docker in production environments.

Responsibilities

• Build and validate predictive models for programmatic advertising.
• Design offline evaluation frameworks using inverse propensity scoring and doubly-robust estimators.
• Define exploration strategies and propensity logging to support reliable evaluation.
• Calibrate and optimize models for advertisers while monitoring ranking and calibration.
• Develop scalable training pipelines across hourly, daily, and weekly schedules.
• Maintain model registry workflows with lineage and auditable promotions.
• Implement per-advertiser model instances with isolated configurations.
• Publish models with freshness SLAs and documented fallbacks.
• Run shadow deployments and champion/challenger experiments with production-grade logging.
• Monitor drift, calibration decay, and label latency in production environments.
• Ensure reproducibility with pinned environments and reproducible data snapshots.
• Prepare technical docs and transfer knowledge to engineering and data teams.

Skills

Python development

SQL proficiency

ML engineering

Production ML systems

Kubernetes & Docker

CI/CD pipelines

Model registry

Experimentation & evaluation

English communication

Tools

XGBoost

LightGBM

CatBoost

MLflow

Kubeflow

Airflow

Argo

Terraform

Job description

Sigma Software is seeking a Senior Machine Learning Engineer to build predictive models for a large programmatic advertising platform. You will design real-time scoring, ranking, and optimization components, and own end-to-end model lifecycles.

The role emphasizes production-grade ML systems, Kubernetes and Docker, MLflow/Kubeflow, and scalable training pipelines. Remote work with cross-team collaboration across distributed engineers.