Data Scientist (Fintech)

Location: Sofia, Bulgaria — office; Varna, Bulgaria — hybrid

Company

hirify.global develops payment, multicurrency account, and e-commerce solutions that help businesses accept payments and grow.

What you will do

• Build and maintain production machine learning models for CLTV, churn, propensity to buy, NMLP, and fraud detection.
• Develop transaction classifiers, merchant anomaly detectors, and new-account risk scorers.
• Contribute model outputs to Next Best Action decisioning across Sales, Marketing, and product touchpoints.
• Design end-to-end ML pipelines covering data ingestion, feature engineering, training, evaluation, and deployment.
• Run A/B tests, uplift tests, and multi-armed bandit evaluations to measure incremental impact.
• Monitor production models for degradation, data drift, and quality issues while documenting improvements.

Requirements

• 3–5 years of applied data science, machine learning, or statistical modelling experience with production models.
• Strong Python skills with pandas, NumPy, scikit-learn, XGBoost or LightGBM, plus PyTorch or TensorFlow.
• Knowledge of supervised and unsupervised learning, classification, regression, clustering, survival analysis, and time-series modelling.
• Experience with SQL, large-scale structured and semi-structured data, and cloud data warehouses; GCP and BigQuery are preferred.
• Familiarity with MLflow or Weights & Biases, REST APIs, batch inference, LLM APIs, and an agentic AI framework.
• Understanding of responsible AI, including fairness assessment, explainability, bias detection, and mitigation.

Nice to have

• Experience in fintech, payments, banking, or e-commerce.
• Workflow orchestration with Airflow, Prefect, or Dagster.
• Causal inference, LLM fine-tuning, RAG pipelines, tool-use agents, or graph-based fraud detection.
• Streaming feature engineering with Kafka, Pub/Sub, or Spark.

Culture & Benefits

• International team working in a technology-focused environment.
• Annual salary reviews, promotions, performance bonuses, and training opportunities through hirify.global Academy.
• LinkedIn Learning access and an annual individual training and development budget.
• 25 days of annual paid leave, increasing to 30 days, plus comprehensive health insurance with dental and optical coverage.
• Monthly meal vouchers worth EUR 102.26, a Multisport card, and a covered public transport pass for Sofia.
• Team-building activities, social events, free office refreshments, and a referral bonus.

Hiring process

• Submit a CV in English.
• Applications are reviewed confidentially, and only shortlisted candidates are contacted.