Software Engineer, Backend

Mistral AI

Paris, France

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.

What you will do

Depending on your skills and field of expertise, you will be involved in key components of our technology, including:

Backend Development:

Design, develop and maintain scalable, robust backend features and APIs using modern frameworks.
Ensure high performance and reliability across our distributed systems.
Contribute to systems powering authentication, billing, AI tooling, observability, connectors, and developer experience.

System Architecture:

Design and implement efficient, secure and scalable architectures that support our fast-growing products.
Collaborate with infrastructure teams on deployment, monitoring, and performance optimization.

Code Quality:

Write clean, maintainable and well-documented code.
Participate in code reviews and contribute to technical standards and best practices.

Cross-functional Collaboration:

Work closely with product managers, front-end engineers, designers and data/AI engineers to deliver end-to-end features.
Partner with teams across AI Studio, Le Chat & Mistral Code to ensure consistent platform-wide experience.

Problem-Solving & Innovation:

Tackle complex engineering challenges, from distributed systems to AI product integration.
Stay up-to-date with new technologies (e.g., AI/LLM integration, observability, or backend frameworks) and bring them into production when relevant.

About you

Degree in Computer Science, Software Engineering, or equivalent practical experience.
Proficiency in Python or another backend language (JavaScript/TypeScript, C#, Golang). Engineers are assessed in their preferred language during a live coding session.
Strong understanding of backend fundamentals: APIs, databases, caching, messaging systems and distributed architectures.
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.