Overview

Job title: ML Systems Engineer - Model Training and Infrastructure (SWE-focused LLMs)

Location: London; full in-office working as default

Start date: ASAP

Compensation: £80,000 - £110,000 Base Salary & £80,000 - £110,000 Share options.

The role

We’re looking for an ML Systems Engineer to collaborate in training our Lumen models – our open‑source–based software engineering LLMs.

This is a unique, interdisciplinary role that involves developing and deploying our reinforcement learning (RL) training environments, working on synthetic data pipelines at massive scale and running fine-tuning jobs to train the next generation of SWE models used in both our self-serve and enterprise products.

We want to ensure the models we train write readable, maintainable code that fits with the architectural patterns in the codebase. We believe we’re in the anti-slop era of coding agents, whe...