LLM Pretraining Scaling Engineer

Humanloop; Greater London; On-site; GBP 57,000 - 73,000; Full time

Benefits offered by this job

Visa sponsorship where possible

Generous vacation & parental leave

Equity donation matching

Job summary

Anthropic is seeking a research engineer to join the ML Performance and Scaling team in London, working on production pretrained models and performance optimization.

You will own parts of the training pipeline, debug across the stack, and design experiments to improve efficiency and uptime while collaborating with teams in London and San Francisco. The role requires in-office presence in London several days per week and requires strong communication under pressure.

Qualifications

• Hands-on experience training LLMs or deep expertise with JAX/TPU/PyTorch.
• Ability to work across research and engineering with a roughly 50/50 split.
• Bachelor's degree or equivalent required.
• Interest in on-call production systems and high-pressure launches.

Responsibilities

• Own production pretraining pipeline components, including operations and observability.
• Debug complex issues across the full stack—from hardware to training dynamics.
• Design experiments to improve training efficiency and uptime.
• Respond to on-call incidents during model launches and coordinate solutions.
• Build production logging, monitoring dashboards, and evaluation infra.
• Collaborate with teams in SF and London and with specialist groups.
• Document systems, debugging approaches, and lessons learned.

Skills

LLM training experience

JAX

TPU

PyTorch

distributed systems

debugging

on-call readiness

cross-time-zone collaboration

Education

Bachelor's degree or equivalent

Tools

PyTorch

Job description

Anthropic is seeking a research engineer to join the ML Performance and Scaling team in London, working on production pretrained models and performance optimization.

You will own parts of the training pipeline, debug across the stack, and design experiments to improve efficiency and uptime while collaborating with teams in London and San Francisco. The role requires in-office presence in London several days per week and requires strong communication under pressure.