Lead NLP & Ranking Scientist - Transformer AI

GlobalLogic Inc.; Polska; On-site; PLN 320,000 - 520,000; Full time

Job summary

GlobalLogic, a Hitachi Group Company, is seeking a Lead Applied Scientist – NLP & Ranking in Poland to lead advanced ML/IR efforts for threat intelligence workflows. You will fine-tune ModernBERT, design ranking cascades, and leverage LLM post-training techniques to boost analyst decision-making.

Open to candidates based in Poland, Romania or Ukraine, with 5–10 years of experience in production ML systems and strong PyTorch/Hugging Face expertise.

Qualifications

• MSc or PhD in NLP, information retrieval or machine learning with publications, or equivalent industry research experience.
• 5+ years of applied ML, with models in production use.
• Deep experience fine-tuning transformer encoders with PyTorch and Hugging Face.
• Multi-label and imbalanced classification, probability calibration and threshold optimization.
• Learning from user feedback: learning-to-rank, active learning, bandit/exploration methods or counterfactual evaluation.
• Rigorous experiment design and statistical analysis.
• ModernBERT or other long-context encoder models.
• Multi-stage ranking or recommender systems.
• LLM post-training (SFT, LoRA, DPO), reward or judge models, and reranker or embedding fine-tuning.
• Vertex AI Training and Pipelines.
• Experience in security, threat intelligence or fraud.

Responsibilities

• Fine-tune, evaluate and calibrate ModernBERT for multi-label alert classification and high-recall shortlisting.
• Design the two-stage triage cascade: model thresholds, the hand-off to the LLM, and how each stage is measured.
• Convert analyst feedback into training data through label cleaning, active learning and defined retraining criteria.
• Correct for selection bias through exploration sampling of rejected alerts and counterfactual evaluation.
• Design the dynamic few-shot strategy: how decision points are represented, how examples are selected, how conflicting or stale human decisions are handled.
• Define the feedback and reward schema with the Lead Agent Engineer.
• Set offline and online evaluation, and review retrained models before production promotion.

Skills

NLP

Machine Learning

Information Retrieval

Ranking

Education

MSc/PhD in NLP/IR/ML

Tools

Hugging Face Transformers

HuggingFace

PyTorch

RAG

Statistics

Job description

GlobalLogic, a Hitachi Group Company, is seeking a Lead Applied Scientist – NLP & Ranking in Poland to lead advanced ML/IR efforts for threat intelligence workflows. You will fine-tune ModernBERT, design ranking cascades, and leverage LLM post-training techniques to boost analyst decision-making.

Open to candidates based in Poland, Romania or Ukraine, with 5–10 years of experience in production ML systems and strong PyTorch/Hugging Face expertise.