Sandbox Platform Engineer - Scalable Systems & Rust

Wwshemi; Paris; Hybrid; EUR 90,000 - 120,000; Full time

Job summary

Mistral AI is hiring a Research Software Engineer for the Sandboxes team in Paris. You will design, build, and operate a platform that runs isolated environments for untrusted code at scale across Kubernetes clusters, spanning distributed systems and low-level virtualization.

You will write robust systems code in Rust and Python, contribute to CI/CD and observability, and collaborate with researchers and ML engineers to turn needs into platform features in a small, high-ownership team.

Qualifications

• A strong background in software engineering and distributed systems, with experience building and operating large-scale infrastructure.
• Deep expertise in at least one of: Kubernetes and cluster operations, cross-cluster networking, observability, or low-level virtualization.
• Fluency in Python or Rust; comfortable writing systems code where performance and security matter.
• Strong software-design instincts: modular code, testing, CI/CD, observability, and a bias for reliability.
• A self-starter who learns fast. Core skills matter more than specific tools - we value meta-learning ability and motivation highly.
• Low-ego, collaborative, and comfortable with ambiguity in a small, high-ownership team.

Responsibilities

• Design, build, and operate the sandboxing platform that runs untrusted code at scale across multiple Kubernetes clusters.
• Develop the sandbox runtime leveraging Firecracker, enabling fast startup, snapshotting, and efficient scheduling.
• Obsess over performance and latency optimisation allowing us to reach millions of concurrent sandboxes.
• Write robust, well-tested systems code in Rust and Python; review code, CI/CD, and observability across the platform.
• Own cross-cluster networking, security boundaries, isolation guarantees and monitoring for suspicious activity.
• Collaborate with researchers and ML engineers who use sandboxes for synthetic data generation and RL training, turning their needs into platform features.

Skills

Software engineering

Distributed systems

Python

Rust

CI/CD

Observability

Security

Tools

Kubernetes

Firecracker

GPU clusters

CI/CD tooling

Job description

Mistral AI is hiring a Research Software Engineer for the Sandboxes team in Paris. You will design, build, and operate a platform that runs isolated environments for untrusted code at scale across Kubernetes clusters, spanning distributed systems and low-level virtualization.

You will write robust systems code in Rust and Python, contribute to CI/CD and observability, and collaborate with researchers and ML engineers to turn needs into platform features in a small, high-ownership team.