Research Engineer, Pretraining Scaling (London)

Own critical aspects of the production pretraining pipeline, including model operations, performance tuning, observability, and reliability.
Debug and resolve issues across the full stack—from hardware and networking to training dynamics and evaluation infrastructure.
Design and run experiments to improve training efficiency, reduce step time, increase uptime, and boost model performance.
Respond to on-call incidents during model launches, diagnosing problems quickly and coordinating solutions across teams.
Build and maintain production logging, monitoring dashboards, and evaluation infrastructure.
Add new capabilities to the training codebase (e.g., long-context support or novel architectures) and collaborate across teams in different locations.