Senior AI Backend Engineer - France and Poland

Lum Apps AI Agents Platform Team

Lum Apps is now more than just an Employee Experience Platform — it is an AI-powered Employee Hub that supports companies in their digital transformation of communication, collaboration, and engagement with their customers, partners, and above all their employees. Our platform is a proven leader in this dynamic market with a truly unique vision and product. It has been deployed by Fortune 500 clients around the world and is delivering meaningful business benefits.

Lum Apps is identified as a leader in Gartner's Magic Quadrant for Intranet Packaged Solutions as well as in Intranets Forrester Wave, and regularly selected for the French Tech Next
40/120 program.

In 2025, Lum Apps strengthened its leadership position by partnering with Beekeeper, a pioneer in frontline employee experience solutions. This strategic collaboration expands our reach and impact across all types of workers — from HQ to the frontline.

Our mission:
To make people feel that they belong and have a purpose. To create an environment where all employees are engaged and work together towards the same goal. Over 700 leading companies trust our solution to:

• Improve the productivity of their teams with our AI-powered Collaborative Experience Platform integrated with both Google and Microsoft collaborative suites,
• Transform employees into real ambassadors of their company,
• Make employees more efficient and better connected to their peers and relevant information, regardless of their location, with the tools and information they need at their fingertips,
• Help companies reduce turnover, accelerate employee onboarding, better collaborate and share knowledge, and even improve their customer experiences.

With a team of over 600 Lumies spread across 11 offices (Lyon, Paris, Lille, Sophia Antipolis, London, Barcelona, Hamburg, Austin, Tokyo, Zurich, Krakow), we support large enterprises all around the world. Over the past year, we have been driving an ambitious phase in our journey under the impulse of our new shareholder Bridgepoint, aimed at propelling us to become the clear leader in our market and shine worldwide in our industry.

We are looking for individuals who are excited to actively participate in this transformation.

If these core values sound like you: "be bold, do amazing things", "say what you mean, do what you say", "one team, same mission", "always be evolving": apply now!

The AI Agents Platform Team is at the heart of Lum Apps' most ambitious product bets. We design, build, and evolve the backend systems that power AI-driven experiences across the platform — from conversational agents and agentic workflows to RAG pipelines, multi-agent orchestration, and real-time streaming infrastructure.

Our backend scope includes:

• Agent Engine: the core orchestration layer powering multi-agent systems using Google ADK and AWS Strands, with LLM routing, tool execution, stateful session management, and real-time streaming via the AG-UI protocol and Server-Sent Events
• RAG & Knowledge Retrieval: retrieval-augmented generation pipelines that connect agents to Lum Apps content, with source attribution, reranking, and sub-agent exploration
• Agent Studio Backend: the data layer and API surface for creating, configuring, and governing AI agents at scale — tools, permissions, feature flags, YAML-driven agent definitions, and multi-tenant architecture
• Observability: tracing and metrics via Langfuse and Open Telemetry to monitor LLM calls, tool invocations, and agent behavior in production

As a Software Engineer (Backend), you will own meaningful end-to-end contributions on the most technically complex parts of our stack. You will work alongside senior engineers, backend specialists, and AI researchers, with direct exposure to the full lifecycle of AI-powered features — from database schema to production deployment.

• Technical Ownership & Delivery Independently scope and implement solutions for your team's projects. Make well-reasoned design decisions, identify tradeoffs and risks, and select the appropriate level of abstraction. Handle open-ended problems and ambiguity well, and ship frequently…