Staff AI Platform Engineer: Research-Driven & Hands-On

Dex; Greater London; Hybrid; GBP 150,000 - 200,000; Full time

Job summary

Dex seeks a Staff or Principal-level AI research engineer to own major AI and research-engineering areas, from problem definition to measurable production impact. This role centers on hands-on work with clear technical authority, not a management track.

You will turn ambiguous problems into research questions, roadmaps, and success metrics, influencing other engineers through credibility while working from London or Paris.

Qualifications

• Deep hands-on experience training, fine-tuning, or post-training models.
• Strong understanding of modern AI/ML, model optimization, evaluation, and RL techniques with production-quality software engineering.
• Ability to translate highly ambiguous technical or research problems into clear plans and long-term initiatives.
• Demonstrated leadership through technical credibility, guiding multiple contributors without line management authority.
• Willingness to work from London or Paris, where the engineering hubs are located.

Responsibilities

• Define and lead technical direction for core AI platform areas, from ambiguous problems to clear, measurable outcomes.
• Design and implement systems for training-data creation, curation, model fine‑tuning, and post‑training optimization.
• Develop and improve agent harnesses, sandboxed execution environments, and robust feedback loops for continuous learning.
• Rigorously evaluate model interventions and agent improvements, establishing baselines and deciding when to iterate, scale, or pivot.
• Influence technical decisions across the team, providing guidance and expertise while remaining deeply embedded in code and experimentation.

Skills

Hands-on ML

Model tuning

Reinforcement learning

Production engineering

Technical leadership

Tools

Python

PyTorch

Git

Job description

Dex seeks a Staff or Principal-level AI research engineer to own major AI and research-engineering areas, from problem definition to measurable production impact. This role centers on hands-on work with clear technical authority, not a management track.

You will turn ambiguous problems into research questions, roadmaps, and success metrics, influencing other engineers through credibility while working from London or Paris.