CareerPlan

Research Scientist / Engineer – Reinforcement Learning Infrastructure

London, UKFull-time2026-10-08 → 2026-11-11

Core

Design, build, and scale distributed reinforcement learning post-training systems for large language models, orchestrating training, rollout, environment, and reward workloads across thousands of GPUs.

Role type

Senior IC reinforcement learning infrastructure engineer

Builds

Distributed RL post-training systems, high-throughput rollout generation, RL environments for agentic tasks, and reward infrastructure

Domain

Artificial Intelligence / Large Language Models / Reinforcement Learning

Deliverable

production ML models

Required skills

Reinforcement learning post-training (PPO/GRPO/RLHF/RLVR), distributed PyTorch training (FSDP, Tensor/Pipeline/Expert Parallel), RL environment design, reward modeling and verification, GPU cluster management, NCCL/MPI networking, vLLM/SGLang integration, Ray orchestration

Preferred skills

Asynchronous/disaggregated trainer-rollout architectures, Kubernetes orchestration, research contributions in RL for LLMs

Technologies

PyTorch, FSDP, vLLM, SGLang, Ray, Kubernetes, NCCL, MPI, veRL, OpenRLHF, TRL