Confidential company, Engineering
RL Research Engineer at well-funded cybersecurity AI startup
- Location
- London, United Kingdom
- Compensation
- Up to £350k (Including Equity)
Are you an RL expert looking to build the front line of AI defense? Join a high-pedigree team in London as an RL Research Engineer and lead the post-training for specialist models that prevent autonomous agent attacks.
With a total compensation package up to £350k and significant equity, you will own the end-to-end training infrastructure and help define how the world secures agentic systems. This is a rare opportunity to apply cutting-edge RLHF and DPO techniques to critical security challenges at a top-tier VC-backed startup.
What's the next step?
Confidential company are hiring from Jack's network. Talk to Jack for free and get a direct introduction to the team, if a good fit.
Role overview
As an RL Research Engineer, you will own the post-training pipeline for specialist language models that detect security threats in real-time. You will design and ship RL pipelines—including RLHF, DPO, and GRPO—to classify malicious trajectories. Your work ensures autonomous systems are resilient against adaptive attacks, providing critical security infrastructure for enterprise AI.
About the company
Well-funded cybersecurity AI startup
What you will do
- Design and ship RL post-training pipelines such as RLHF, DPO, and GRPO to optimize models for real-time security threat classification.
- Build and maintain scalable training infrastructure end-to-end, including distributed training, evaluation harnesses, and rigorous regression testing.
- Develop custom reward models and preference optimization systems tailored to identifying complex, long-horizon malicious agent trajectories.
Who this is a fit for
- Proven hands-on experience with RL post-training for language models (RLHF, DPO, or similar) in a production or research setting.
- Strong engineering fundamentals with the ability to operate complex training pipelines at scale using PyTorch, JAX, and distributed computing.
- A background in machine learning research, ideally with a PhD or equivalent expertise in optimization, alignment, or reinforcement learning.
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Why this role is remarkable
- Join a high-pedigree founding team building mission-critical defense infrastructure for the next generation of autonomous AI systems.
- Backed by top-tier VCs, this seed-stage startup addresses the urgent need for adaptive security in an increasingly agent-led threat landscape.
- Take significant ownership as you shape the core detection logic and training infrastructure for a highly technical, high-impact product.
How Jack & Jill work together
What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter working for the company. She recruits from Jack’s network.
If your profile’s a match and Confidential company wants to meet, Jill will make the intro. In the meantime, Jack will send you excellent alternatives.