Staff Data Scientist / Machine Learning Engineer (AI)

Location: Worldwide

Salary: EUR 3050–5250 per month gross; final compensation depends on experience, location, and professional growth.

Company

hirify.global is an international technology company developing software solutions for operational efficiency and data-driven decision-making, with expertise strengthened since 2007.

What you will do

• Build and maintain predictive customer lifetime value models with XGBoost, CatBoost, and BG/NBD in a tiered scoring architecture.
• Design calibration layers using normalization methods, haircut scalars, and asymmetric loss functions to produce platform-ready advertising signals.
• Develop BigQuery Gold-layer feature tables with RFM metrics, behavioral embeddings, category affinity, and purchase velocity, while monitoring feature quality.
• Monitor model drift, distribution shifts, residuals, deployment cohorts, and causal contamination in retraining data.
• Maintain identity-resolution algorithms connecting GA4 behavioral identifiers with Shopify transactional identifiers.
• Develop production-grade Python workloads on Google Cloud Run Jobs with Airflow, APIs, automated testing, CI/CD, idempotency, and dry-run safeguards.

Requirements

• 5+ years of hands-on Machine Learning Engineering experience with Python, including development, deployment, and maintenance of production-grade ML models.
• Experience with gradient boosting algorithms such as XGBoost, CatBoost, or LightGBM, including tuning, feature-importance analysis, and advanced evaluation.
• Strong SQL and BigQuery skills for complex feature engineering, scheduled transformations, and data validation.
• Experience deploying and maintaining ML workloads on GCP, including Cloud Run, Airflow/Composer, Vertex AI, and Pub/Sub.
• Understanding of model calibration, business-oriented loss functions, and prediction-error impact on downstream optimization systems.
• Experience integrating ML outputs with external systems through APIs, such as advertising, recommendation, pricing, or bidding platforms.
• English at Upper-Intermediate level or above is required.

Nice to have

• Experience in e-commerce or DTC environments, especially LTV prediction, purchase forecasting, churn modeling, or customer segmentation.
• Knowledge of BG/NBD, Gamma-Gamma, similar probabilistic customer models, or strong Bayesian statistics foundations.
• Experience with advertising integrations such as Google Ads API, Meta Conversions API, or similar server-side tracking systems.
• Knowledge of identity resolution and entity matching, including graph-based stitching, probabilistic matching, or cross-device resolution.
• Experience with Terraform, CI/CD design, and Docker for ML workloads.
• Knowledge of causal inference, advertising A/B testing, or multi-armed bandit optimization.
• Familiarity with AI-assisted development tools and agentic coding workflows such as Claude Code or Cursor.

Culture & Benefits

• Work is available worldwide.
• Access to company BA meetups and compensation for international professional certificates.
• Opportunities for technical, resource-management, and mentoring growth.
• Access to the hirify.global Knowledge Base with courses in negotiation, Agile, product ownership, microservices, API design, SQL, AWS, GDPR, UX/UI, and people management.
• Projects with international businesses and opportunities for professional development.