Senior ML Engineer: Real-Time AdTech Optimization

Sigma Software; United States; À distance; USD 140 000 - 190 000; Plein temps

Résumé du poste

Sigma Software is seeking a Senior Machine Learning Engineer to build production ML for a real-time ad exchange, handling hundreds of millions of requests daily. You will contribute to bid optimization, calibration, and counterfactual evaluation within a scalable ML platform.

You will collaborate with data scientists and engineers to design models for predictive decisioning, audience targeting, and multi-objective optimization, advancing end-to-end ML workflows from experimentation to deployment.

Qualifications

• 5+ years of ML/DS experience with production-grade models.
• Proficient Python with numpy, pandas, and scikit-learn.
• Strong SQL skills and large-scale data handling.
• Hands-on with XGBoost, LightGBM, or CatBoost.
• Experience with A/B testing and offline/online evaluation.
• Knowledge of calibration methods and SHAP/interpretability.
• English at Upper-Intermediate level or higher.
• Experience in AdTech modeling including CTR/CVR and RTB systems.

Responsabilités

• Build censored bid-landscape models to estimate clearing-price distributions from partially observed auction data.
• Develop real-time win probability estimation models responsive to bid pricing dynamics.
• Design and implement hierarchical lift estimation models with confidence-bound-based selection strategies.
• Build conversion propensity models using sparse, delayed, and aggregate-only labels.
• Develop look-alike audience modeling approaches using positive-unlabeled learning and embedding-based nearest-neighbor techniques.
• Implement advertiser-level calibration strategies while monitoring ranking and calibration quality.
• Design robust offline evaluation frameworks using inverse-propensity scoring, doubly-robust estimators, and importance reweighting.
• Define exploration strategies and propensity logging approaches to ensure reliable downstream correction and evaluation.
• Develop constrained optimization mechanisms for campaign objectives, pricing constraints, and volume targeting.
• Contribute to data diagnostics, capability assessments, and evidence-based model recommendations.
• Collaborate with Customer data science team during post-launch tuning and validation.

Connaissances

Python

SQL

Spark/PySpark

XGBoost/LightGBM/CatBoost

A/B testing

SHAP interpretation

Feature engineering

Statistics

Vertex AI

English communication

Outils

Vertex AI

Description du poste

Sigma Software is seeking a Senior Machine Learning Engineer to build production ML for a real-time ad exchange, handling hundreds of millions of requests daily. You will contribute to bid optimization, calibration, and counterfactual evaluation within a scalable ML platform.

You will collaborate with data scientists and engineers to design models for predictive decisioning, audience targeting, and multi-objective optimization, advancing end-to-end ML workflows from experimentation to deployment.