Member of Technical Staff, Integration/RL (Research Engineer) at Cohere (Paris or remote in Europe)

Job Description

Cohere’s integration team is hiring a research engineer to develop and scale machine-learning algorithms and infrastructure for LLM post-training, with a focus on large, distributed reinforcement learning. The role improves the post-training codebase, optimises algorithms and scales distributed RL. It is listed for Paris, and applicants can work anywhere between UTC−6 and UTC+1.

At a glance

• Team: Integration / RL (post-training)
• Location: Paris, London, Toronto, San Francisco or New York offices, or remote within UTC−6 to UTC+1
• Focus: Distributed RL for LLM post-training
• Apply: open until filled (re-checked 14 October 2026)

What you would do

• Design and write high-performance, scalable software for training models
• Build tools that make post-training research easier
• Optimise post-training algorithms and scale distributed RL
• Write design documents and careful experiments with the wider team

Why this role matters

Reinforcement learning after pre-training is now where much of a language model’s usefulness is shaped, and running it across thousands of GPUs is a hard systems problem. This role improves the shared code that Cohere’s researchers use every day, which multiplies the whole team’s output. The flexible time-zone rule makes it open to strong candidates across Europe and the Americas.

What Cohere is looking for

• Strong software engineering in Python and ML frameworks
• Experience with distributed training or large-scale ML systems
• Interest in reinforcement learning for language models

Nice to have

• Experience with RL post-training (RLHF, RL from verifiable rewards) at scale

Pay and location

Cohere lists pay ranges on the posting that vary by location; check the posting for the range that applies to you.

How to apply

Apply through the official Cohere job posting. Cohere’s posting does not give a closing date, so the role is open until filled; ResearchJobs.in will re-check this listing on 14 October 2026. Check the posting for location and work-authorisation details before you apply.

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