Security Engineer / Research Engineer, RL SecurityActive$320K

The opportunity

Reinforcement learning is how Claude learns to reason, write code, and act autonomously over long horizons. At frontier scale, an RL run is a large distributed system: training, sampling, and environment execution run concurrently across a large fleet of accelerators and hosts.

What you'll do

  • Design, build, and operate security controls for RL training systems and the infrastructure they run on

  • Work across the stack (orchestration, environments, training, inference) wherever the work is needed

  • Review designs and code across the RL stack, find security problems, and fix them

  • Build shared libraries and tooling that other RL engineers and researchers build on

  • Build the observability needed to understand what these systems are doing

  • Work with researchers and performance engineers to make sure security changes: preserve training correctness and performance

What they're looking for

  • Experience running ML training or inference infrastructure at scale
  • Experience with infrastructure security, such as isolation, access control, networking, or identity
  • Experience with container orchestration such as Kubernetes, and with: sandboxed or virtualized code execution at scale
  • Experience building observability for large fleets
  • Experience supporting research teams or other fast-moving internal users
  • Familiarity with reinforcement learning or large language model training workloads