Software Engineer (Freelance)
Mistral AI
Software Engineering
Paris, France
Posted on Feb 17, 2026
About Mistral
At Mistral AI, we believe in the power of AI to simplify tasks, save time and enhance learning and creativity. Our technology is designed to integrate seamlessly into daily working life.
We democratize AI through high-performance, optimized, open-source and cutting-edge models, products and solutions. Our comprehensive AI platform is designed to meet enterprise needs, whether on-premises or in cloud environments. Our offerings include le Chat, the AI assistant for life and work.
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 France, USA, UK, Germany and Singapore. We are creative, low-ego and team-spirited.
Join us to be part of a pioneering company shaping the future of AI. Together, we can make a meaningful impact. See more about our culture on https://mistral.ai/careers.
Role summary
We are seeking passionate and skilled software engineers to join our team. As a Backend Engineer, you’ll contribute to the development of the core systems powering our three main products, AI Studio, Le Chat & Mistral Code, shaping how users and developers interact with our AI platform at scale. You’ll work on building reliable, high-performance backend systems and APIs that serve millions of users and developers. Your work will directly impact the developer and user experience, making it more engaging, efficient, and intuitive. We welcome engineers at all levels from fresh graduates to senior and staff engineers and who are eager to learn, collaborate and ship impactful products.
What you will do
Depending on your skills and field of expertise, you will be involved in key components of our technology, including:
Full stack Product Development
• Design, develop, and maintain scalable and robust features ensuring seamless integration between front-end and back-end systems.
• Ensure high performance, reliability and scalability across our distributed systems.
• Contribute to systems powering AI-assistants, developer experience, authentication, billing, AI tooling, observability, connectors, search and more.
AI Engineering
• Design and run evaluations for your product area: reference tests, heuristics, model-graded checks tailored to search relevance, chat quality, document understanding, or audio performance.
• Define and track metrics that matter: task success, helpfulness, hallucination proxies, safety flags, latency, cost.
• Improve core behaviors in your product area, whether that's memory policies, intent classification, routing, tool-call reliability, or retrieval quality.
Data Engineering
• Design, build, and maintain scalable data pipelines, ETL processes, and analytics infrastructure. Automate data quality checks and validation processes.
• Collaborate with cross-functional teams to understand data needs and deliver high-quality, actionable solutions, eg work closely with machine learning teams to support model training, deployment pipelines, and feature stores.
• Optimize data storage, retrieval, processing, and queries for performance, scalability, and cost-efficiency.
Development Operations
• Build, monitor, and enhance CI/CD pipelines to streamline development workflows and accelerate deployments.
• Design, operate and maintain scalable, reliable and secure multi-cloud infrastructures
• Identify areas for improvement and create innovative solutions that enable high developer velocity
Frontend Web Engineer (Creative & Brand Experience)
• Build and maintain our websites. Using modern frameworks like React, Next.js, Svelte and Astro, you’ll develop responsive, accessible pages and reusable components.
• Create interactive experiences. Bring our brand to life with animations and micro-interactions that delight users while ensuring strong performance and accessibility.
• Collaborate across disciplines. Work closely with designers, marketers and developers to launch high-impact pages, campaigns and microsites.
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You can find more details about our open contractor roles >> here <<
About you
While the required skills vary by role, here are a few essential criteria for success in any engineering position:
• Degree in Computer Science, Software Engineering, or equivalent practical experience.
• Proficiency in one of the following languages: Python, TypeScript, Golang.
• Strong problem-solving abilities and attention to detail.
• Ownership mindset capable of shipping end-to-end features with minimal oversight.
• Excellent communication skills and collaborative attitude.
• Team-oriented, low-ego mindset and curiosity for learning.
Fast-Track Hiring Process
• Intro call with a recruiter — 15 min
• Technical rounds — usually 2 x 45 min depends on the role
• Interview with a technical lead — 30 min
Our Culture
We're driven to build a strong company culture and are looking for individuals with solid alignment with the following:
• Reason with rigor
• Are you audacious enough?
• Make our customers succeed
• Ship early and accelerate
• Leave your ego aside
Engineering blog
Our first Engineering blog post is live, you can check it out here !