Top Software Engineer Jobs in Lille

Dragonfly is seeking Software Engineers for various portfolio companies, focusing on crypto technologies. Engineers of all experience levels are needed across multiple stacks.

As a Distributed Systems Engineer, you'll design and evolve LiveKit's core systems, implement resilient architectures, and enhance reliability and developer velocity, working on critical features in production environments.

The Senior Infrastructure Engineer will manage and scale LiveKit's core infrastructure, focusing on reliability and performance, while working on Golang code and automation for distributed systems.

Design and evolve core control, data, and observability systems; implement resilient region-spanning architectures; build libraries, protocols, and tooling; diagnose and harden critical paths using metrics, tracing, and testing; and shape platform capabilities across identity, scheduling, observability, and distributed state management.

Design, implement, and manage LiveKit's infrastructure, focusing on performance, reliability, and automation while ensuring effective incident management and coordination with vendors.

The role involves designing and evolving core systems at LiveKit, implementing resilient architectures, and building tools to enhance system reliability and developer speed. Strong distributed systems experience and programming skills are essential.

Design, implement, and operate low-latency, highly available distributed control, data, and observability systems. Build region-spanning architectures, libraries, protocols, and tooling; diagnose and harden critical paths using metrics, tracing, testing, and real traffic; and shape platform capabilities around identity, scheduling, observability, and distributed state management.

The Staff Tech Lead Software Engineer will drive technical vision, mentor teams, oversee code quality, and facilitate collaboration between engineering and product teams.

As a Senior Software Engineer, you will develop and manage a MongoDB solution on various platforms, ensuring reliability and security while contributing to a small team focused on impactful projects.

Build and improve Restream’s web interfaces and user-facing features for the AI Clips team. Design UI and business logic, collaborate with product designers, participate in code reviews, improve system reliability, and evaluate emerging technologies. The role requires strong JavaScript and TypeScript expertise, advanced React knowledge, CSS preprocessor experience, and familiarity with backend development, cloud infrastructure, containers, and continuous deployment.

Lead full‑stack development of OpenGRC: build correlation, verification, and quantification engines. Own end‑to‑end stack (React/TypeScript frontend, Node.js backend, PostgreSQL), define architecture, mentor the squad, and shape product direction for a data‑driven GRC platform integrated with CTI and OpenAEV.

Lead design and ownership of shared libraries, Spring Boot starters, and agentic frameworks. Set standards for agent orchestration, evaluations, and guardrails. Mentor teams on Python-based agents (LangChain/LangGraph), drive adoption, prototype research directions, and improve developer experience across Kotlin backend and client libraries.

Senior software engineer responsible for designing, developing, and maintaining business-critical applications. Collaborate with product, QA, DevOps, and stakeholders to translate requirements, implement scalable Java/Python solutions on AWS, address technical debt, improve performance, participate in code reviews, support releases, and ensure application stability and continuous improvement.

Own and evolve Scaleway's managed-database platform: design and ship features, automate deployments and upgrades, optimize performance, diagnose incidents, and participate in second-level on-call rotations, working with DBAs, SREs, and product teams.

Build core components of a diagnostic and personalization platform: backend data pipelines, frontends, services for genomic data ingestion, ML model integration, APIs, and cloud infrastructure. Collaborate with product and ML teams, iterate on prototypes and MVPs, and make architectural decisions supporting scalability and reliability.

Design and build the on-prem software stack for ModelVault appliances: containerized inference engines, model integration (LLMs/vision), deployment tooling, CLIs/GUI/APIs, OS and GPU setup, remote updates, telemetry, and collaborate with customers and founding team to iterate and scale the engineering org.

Design, implement, and operate a cloud-native platform: build and maintain Kubernetes clusters and custom operators, write production Go code for platform services and automation, optimize multi-cloud infrastructure for cost and reliability, improve observability and CI/CD/IaC automation, support incident response and system hardening, and collaborate with engineering teams to improve developer experience and reliability at scale.

Seeking a Senior Software Engineer to build AI inference systems. Responsibilities include optimizing GPU kernels, architecting inference stacks, and defining benchmarking methodologies. Requires strong programming skills and experience in ML systems.

Design, implement, and maintain Firefox security architecture and cryptography stack (WebPKI, cryptographic protocols). Build web platform security features, debug multi-threaded cross-platform native code, improve performance and memory usage, collaborate across teams, and contribute to technical design and standards-based implementations.

Build and ship browser-based 3D interactive features using React, Three.js, and WebGL; integrate frontend with a C++ computational backend on AWS; use AI tools (Claude Code) to accelerate development; prototype AI-powered product features; and collaborate with clinical scientists, UX, ML engineers, and QA.

Build foundational agent infrastructure for an AI assistant: orchestration, tool execution, context management, evaluation, and trust/permissions. Ship reliable, observable, and secure backend systems, launch agentic features, own core infrastructure, participate in on-call, and mentor others.

Design, build, ship, and maintain end-to-end product features across frontend, backend, and data layers. Own projects from definition through production, improve reliability and scalability, collaborate with product and design, mentor engineers, and engage with customers to solve real user problems.

Lead optimization of concurrent systems, scale backend microservices, and collaborate with developers and engineers on deployment for retail solutions.

Design and build the XTM One core platform as a Senior Full Stack Engineer using TypeScript and Python. Define architecture for AI integrations, implement visualization flows, logging, and agent configuration, prototype rapidly, engage with the open-source community, and help create development processes and team culture.

Improve reliability, observability, and scalability of Enode's connectivity layer. Build and maintain API integrations with OEMs and energy partners, reduce incidents, enhance monitoring and alerting, drive complex projects to release, uphold code quality and testing, collaborate with product, and mentor teammates while applying AI tooling strategically.