Research Engineer, Sandboxes

Mistral

Paris +3 more

On-site

Who this role is best for

Candidates with distributed systems experience and a focus on infrastructure will find this role in sandboxing platform development at Mistral.

Best fit for

Candidates with distributed systems experience and a passion for scalable infrastructure design
— “design, build, and operate the platform that runs isolated environments for untrusted code at massive scale”
Individuals skilled in low-level virtualization and performance optimization
— “Obsess over performance and latency optimisation allowing us to reach millions of concurrent sandboxes.”
Engineers who thrive in small, high-ownership teams with a focus on reliability and clean code
— “We are a dynamic, collaborative team passionate about AI and its potential to transform society.”

Things to consider

The role requires a strong focus on systems code rather than ML research
— “This is a software engineering role, not an ML research role.”
The team is small and highly selective, with significant impact expected from each hire
— “you will join a small, senior team where the wrong hire is worse than no hire.”

How to stand out

Emphasize your experience building and operating large-scale distributed infrastructure
— “A strong background in software engineering and distributed systems, with experience building and operating large-scale infrastructure.”
Showcase your ability to write clean, reliable systems code in Rust or Python
— “Write robust, well-tested systems code in Rust and Python; review code, CI/CD, and observability across the platform.”
Highlight your expertise in cross-cluster networking and security boundaries
— “Own cross-cluster networking, security boundaries, isolation guarantees and monitoring for suspicious activity.”

Pace · Fast PacedCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

designed and built sandboxing platform
developed sandbox runtime
optimized performance and latency

Typical background

strong background in software engineering and distributed systemsexperience building and operating large-scale infrastructure

Skills & requirements

Required

Distributed SystemsKubernetesLow-level VirtualizationSystems CodeObservabilitySecurity

Preferred

FirecrackerMicrovmsGPU ClustersCUDAML Workloads

Stack & domain

KubernetesCluster OperationsCross-cluster NetworkingObservabilityLow-level VirtualizationFirecrackerMicrovmsPythonRustCUDAML WorkloadsSREPlatform EngineeringTeamworkCollaborationSelf-starterLearning AbilityMotivationAIDistributed SystemsInfrastructure

About the role

Original posting from Mistral via Ashby

ABOUT MISTRAL
Mistral provides full-stack AI solutions: from frontier models to developer tools, applications, and compute. We partner with enterprises tackling the hardest problems across high-stakes industries like finance, manufacturing, defense, healthcare, and the public sector, co-creating customized AI systems that they can run on their terms.
We are a dynamic, collaborative team passionate about AI and its potential to transform society. Our diverse workforce thrives in competitive environments and is committed to driving innovation. Our teams are distributed between Europe, North America, Asia and the Middle East. We are creative, low-ego and team-spirited.
THE ROLE
As a Research Software Engineer on the Sandboxes team, you will design, build, and operate the platform that runs isolated environments for untrusted code at massive scale. Our work spans distributed systems, low-level virtualization, and product-minded platform design. Engineers on this team move between deep infrastructure work and understanding how researchers actually use the platform.
This is a software engineering role, not an ML research role. You do not need prior ML experience; what matters is writing clean, reliable systems code that scales. You will join a small, senior team where the wrong hire is worse than no hire.
WHAT YOU WILL DO
Design, build, and operate the sandboxing platform that runs untrusted code at scale across multiple Kubernetes clusters, from our own bare metal data centers to hyperscalers.
Develop the sandbox runtime leveraging Firecracker, enabling fast startup, snapshotting, and efficient scheduling without blocking expensive hardware.
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.
WHAT WE'RE LOOKING FOR
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.
NICE-TO-HAVES
Experience with Firecracker, microVMs, or similar virtualization technologies.
Product-mindedness: understanding of how sandboxes are used for synthetic data generation or RL training.
Experience with GPU clusters, CUDA, or ML workloads.
Prior SRE or platform engineering experience at scale.
Open-source contributions or widely used internal tools.
WHAT WE OFFER
We offer a comprehensive benefits package designed to support your well-being, growth, and work-life balance. Benefits vary by country and may include healthcare coverage, parental leave, retirement plans, relocation support, wellness programs, meal and transportation allowances, and other location-specific perks.
For the most up-to-date details on benefits available in your location, please refer to our Benefits page https://app.notion.com/p/mistralai/Benefits-at-Mistral-36e6ba59a7fe836b93dd01737fcc27ef?source=copy_link.
PRIVACY POLICY
Your privacy matters to us. You can learn more about how we handle your personal data in our Applicant Privacy Policy https://legal.mistral.ai/terms/applicant-privacy-policy.

Source: Mistral careers (Ashby)