Senior ML Scientist — Production AI Security

Refractal; Greater London; Presencial; GBP 85 000 - 145 000; Tempo integral

Vantagens oferecidas por esta oferta de emprego

Competitive equity

Pension contribution

Private medical

Relocation support

Resumo da oferta

Refractal is seeking an experienced ML engineer to own the machine-learning models behind our real-time AI threat detections in production.

You will train, tune and ship classifiers for prompt injection, data exfiltration and policy violations, analyse telemetry for drift and latency, and translate regulatory requirements into measurable controls.

Collaborate with security engineers and researchers to continuously improve performance and reduce false positives.

Qualificações

• 5+ years in applied ML or data science, with models shipped to production.
• Strong Python, PyTorch or similar, and solid statistics for evaluation.
• Hands-on NLP and LLM work: fine-tuning, embeddings, classification and LLM-as-judge.
• Experience measuring fuzzy problems, including labelling, agreement and drift.
• Clear communication of trade-offs to engineers and customers.

Responsabilidades

• Train, tune and ship classifiers for prompt injection, data exfiltration, policy violations and other risky AI activity.
• Design low-latency models, including distilled and small models and rules-plus-ML ensembles.
• Analyse production telemetry for drift, blind spots, false-positive cost and new attack patterns.
• Build evaluations and benchmarks for our detection models, and work with security engineers to turn new attacks into training data.
• Turn company policies and regulatory requirements into measurable controls.

Conhecimentos

Python

PyTorch

NLP

LLM

Descrição da oferta de emprego

Refractal is seeking an experienced ML engineer to own the machine-learning models behind our real-time AI threat detections in production.

You will train, tune and ship classifiers for prompt injection, data exfiltration and policy violations, analyse telemetry for drift and latency, and translate regulatory requirements into measurable controls.

Collaborate with security engineers and researchers to continuously improve performance and reduce false positives.