Evaluation Engineer, Applied AI

Wwshemi; Paris; Hybrid; EUR 70,000 - 110,000; Full time

Job summary

Mistral is building frontier LLM evals to shape the next generation of flagship models. As an Evaluation Engineer, you will own evals from start to finish, running workshops with customers and internal teams to identify critical industry use cases and design benchmarks to measure them inside real software.

You will source data, define scoring, and run benchmarks on our models and on competitors, then publish results that guide product and go-to-market decisions.

Qualifications

• 2+ years of industry experience (AI or software) or a PhD.
• Software engineering or research background with runnable code.
• Experience working with customers, industry experts, or teams.
• Experience building something with LLMs.
• Comfort with large datasets and data cleaning.

Responsibilities

• Run discovery with customers and teams to identify high-value use cases.
• Design benchmarks for industry use cases and frontier capabilities and how they’re scored.
• Build evals where agents work inside real software and run on our models and competitors.
• Stress-test evals, identify flaws, and iterate.
• Source data with vendors or create realistic proxy/synthetic data when needed.
• Document and present findings to leaders to inform decisions.
• Help other teams build their own evals with reusable tools.

Skills

Python

LLM evals

Customer-facing

Independent/work with ambiguity

Education

PhD or equivalent

Tools

Python

Job description

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

This is a chance to build the frontier LLM evals that shape the next generations of flagship models.

Could a model design a computer chip, or find the backdoor an attacker left in a network? Public benchmarks can't tell us, as they're generally not a good measure of real work.

As an Evaluation Engineer, you'll own evals from start to finish. You'll run workshops with customers, industry experts and our customer-facing teams to understand their most important industry use cases (e.g., an engineer updating a part in CAD software), and help decide which are worth building first. You'll also look beyond today's use cases and design moonshot evals for work no model can do yet, so Mistral gets there first. Then you'll turn each one into a benchmark, often one where an agent has to do the work inside real software. You'll source the data, decide how to score it, and run it on every new Mistral model and on competitor models.

When our models fall short, you'll work with the post-training teams to close the gap. When they catch up, you'll make the eval harder. You'll write up and present your results so senior leaders can act on them. They also give our go-to-market teams evidence of where Mistral leads.

You'll learn new fields quickly. One month you might be learning how chip designers check their work, and the next how a bank investigates a flagged payment.

The team is new and fast-paced, and you'll have a lot of autonomy. You'll spend a lot of time speaking with people across Mistral to work out what matters most, then decide what to build.

What You Will Do

• Run discovery with customers, industry experts and teams across Mistral, then help decide which use cases are worth building first.
• Design new benchmarks for industry use cases and frontier capabilities, including how they're scored.
• Build evals where agents work inside real software (e.g., CAD and simulation tools), and run them on our models with checks that the results stay reliable over time.
• Stress-test existing evals to find flaws and bugs before we rely on them.
• Source data with expert vendors. Where customer data can't leave the customer, build realistic proxy or synthetic data instead.
• Write up and present what you find so leaders across Mistral can act on it.
• Help other teams build their own evals, with tools and guides they can reuse.

What We're Looking For

Experience

• 2+ years of industry experience (e.g., in software, AI, or consulting), or a PhD.
• A software engineering or research background, with experience writing code that others can build on.
• Experience working directly with customers, industry experts, or other teams (e.g., through consulting, solutions engineering, or research collaborations).
• Experience building something with LLMs.
• Comfort working with large datasets, including building and cleaning them.

Technical

• Strong Python skills.
• Comfortable working in a large, shared codebase and getting your code through reviews by other teams.
• A strong understanding of LLM training, inference, and evaluation.

Communication

• You enjoy speaking with people and is good at it.
• You write clearly. A short doc or deck from you is enough for a busy leader to make a decision.
• Confident presenting to both technical and non-technical audiences.
• Fluent in English.

How you work

• High energy, and you don't need a roadmap. You move independently and handle uncertainty with confidence.
• Proactive and high-agency. You spot what needs doing and get it done.
• You make good decisions about what to build first and can explain why.
• Low-ego, collaborative, and eager to learn.
• Curious, with a track record of learning things outside your work or studies. You can get to grips with a new field in a few weeks.

NICE TO HAVE

• Experience building AI evaluations, especially for industry applications.
• Published research on evals or contributions to open-source evaluation frameworks.
• Experience building datasets, generating synthetic data, developing labelling guidelines, or working with annotation vendors.
• A background in an industry outside software (e.g., engineering, finance, or science).

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).

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